valve Archives

Valve material and valve standards-(5)-packing material

September 3, 2020

Packing /Filler material:
On the valve, the packing is used to fill the space of the valve cover packing chamber to prevent the medium from leaking through the valve stem and the bonnet packing chamber.

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

Requirements for packing.

1. Good corrosion resistance, the filler must be able to withstand the corrosion of the medium in contact with the medium.
2. Good airtightness, the packing will not leak under the action of the medium and working temperature.
3. The friction coefficient is small to reduce the friction torque between the valve stem and the packing.

Types of filler:

1. Soft filler: it is a string woven from plant matter, that is hemp, flax, cotton, jute, etc., or mineral, that is, asbestos fiber, or asbestos fiber with metal wire inside and graphite powder coated on the outside. Pressed molding fillers, and flexible graphite filler materials developed in recent years.
Vegetable packing is often used for low pressure valves below 100°C; mineral packing can be used for valves with 450-500°C. In recent years, the temperature of structural media using rubber O-rings as fillers is generally limited to below 60°C.
The packing on the high temperature and high pressure valve is also made of pure asbestos and flake graphite powder.

2. Hard filler: that is, filler made of metal or metal mixed with asbestos and graphite and filler formed by pressing and sintering of PTFE, metal filler is used less.

Selection of filling material:
The choice of packing should be based on the medium, temperature and pressure. The commonly used materials are as follows:

1. Oil-impregnated asbestos rope, can be selected according to Table 5-2
2. Rubber asbestos rope, can be selected according to 5-3
3. Graphite asbestos rope: The asbestos rope is coated with graphite powder, the usable temperature is above 450°C, and the pressure can reach 16MPA, which is generally suitable for high-pressure steam. Lately, it gradually adopts the compressed herringbone type packing, which is placed in a single circle and has good sealing performance.
4. Polytetrafluoroethylene: This is a kind of filler that is currently widely used. Especially suitable for corrosive media, but the temperature should not exceed 200°C. Generally, it is made by pressing or rod car.

Fig.5-2:

Material	Grade name	shape	size(dia or square)	Max Pressure kgf/cm2	max temp/ °C	application
Oil-impregnated asbestos rope	YS450	F	3,4,5,6,8,10,13,16,19,22,25	60	450	water, steam,air,petroleum products
		Y	5,6,8,10,13,16,19,22,25
		N	3,5,6,8,10,13,16,19,22,25
	YS350	F,Y,N	3,5,6,8,10,13,16,19,22,25	45	350
	YS250	F,Y,N	3,5,6,8,10,13,16,19,22,25	45	250

Note: The shape code F means square, through the heart or one or more layers of weaving; Y means round, with a twisted core in the middle and one or more layers of weaving on the outside; N means twisted.

Fig.5-3:

Material	Grade name	size(dia or square)	Max Pressure kgf/cm2	max temp/ °C	application
Rubber, asbestos, packing	XS450	3,4,5,6,8,10,13,16,19,22,25,28	60	450	steam,petroleum products
	XS350		45	350
	XS250		45	250

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve material and valve standards-(4)-fastener material

September 3, 2020

Fastener materials: Fasteners mainly include bolts, studs and nuts. The fastener directly bears the pressure on the

bolts and nuts for butterfly valve

valve, which plays a key role in preventing the outflow of the medium. Therefore, the selected material must ensure sufficient strength and impact toughness at the operating temperature.

When selecting fastener materials according to medium pressure and temperature, the following table can be selected:

Name	Pn(Mpa)	medium temp /°C
		300	350	400	425	450	530
bolt Stud bolt	1.6-2.5	Q235(A3)		35		30CrMoA	–
	4.0-10.0	35				35CrMoA	25Cr2MoVA
	16.0-20.0	30CrMoA		35CrMoA			25Cr2MoVA
nut	1.6-2.5	Q235(A3)		30		35
	4.0-10.0	30				35	35CrMoA
	16.0-20.0	35					35CrMoA

Heat treatment must be carried out when selecting alloy steel materials. When there are special corrosion resistance requirements for fasteners, stainless acid-resistant steels such as Cr17Ni2, 2Cr13, 1Cr18Ni9 can be selected.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve material and valve standards-(1)

August 26, 2020

What material is WCB/LCB/LCC/WC6/WC in the valve?
W, wrought casting; C, Carbon steel; A, B, C indicate the strength value of steel grades from low to high.

lug type butterfly valve-ductile iron

WCA, WCA, WCC represent carbon steel, ABC represents the strength level, and WCB is commonly used. The corresponding pipe material of WCB should be A106B, and the corresponding forging material should be A105.
WC6 is an alloy steel casting, the corresponding pipe material is about A355 P11, and the forging is A182 F11; there is also WC9, high temperature resistant alloy steel, the corresponding pipe material is about A355 P22, and the corresponding forging is A182 F22.
WC: weldable casting
LCB/LCC (ASTM A352) low temperature carbon steel
ITCS is carbon steel with impact toughness; impact test C=carbon S=steel (A350)
Split body split type, side entry side mounted (referring to the actuator), corresponding to TOP entry top mounted type

Commonly used valve casting and forging carbon steel material table

material	country	standard	material grade name
Casting	China	GB/T 12229	WCA	WCB	WCC
			ZG205-415	ZG250-485	ZG275-485
	USA	ASTM A216/A216M	WCA	WCB	WCC
			UNS J02502	UNS J03002	UNS J02503
Forged	China	GB/T 12228 GB/T 699	25 25Mn 35 40 A105
	USA	ASTM A105/A105M	A105

Low temperature casting parts material name and temperature range

C	C	C-Mn	C-Mo	2.5Ni	Ni-Cr-Mo	3.5Ni	4.5Ni	9Ni	Cr-Ni-Mo
LCA	LCB	LCC	LC1	LC2	LC2-1	LC3	LC4	LC9	CA6NM
J02504	J03303	J02505	J12522	J22500	j42215	j31550	j41500	j31300	j91540
-32	-46	-46	-59	-73	-73	-101	-115	-115	-73

Commonly used valve ASTM Casting and Forged material sheet (ASME B16.5)

ASTM Casting	ASTM Forged	China name	Temp °C	suitable medium
Carbon steel
A216 WCB	A105	20	-29/427	water,steam,air,petroleum products
Low temp Carbon steel
A352 LCB	A350 LF2	16Mn	-46/343
A352 LCC	A350 LF2	16Mn	-46/343
High temp alloy
A217 WC1	A182 F1	20MnMo	-29/454	High temp, High pressure medium
A217 WC6	A182 F11	15CrMo	-29/552	High temp, High pressure medium
A217 WC9	A182 F22	10Cr2Mo1	-29/593	High temp, High pressure medium
A217 C5	A182 F5	1Cr5Mo	-29/650	Corrosive high temperature medium
A217 C12	A182 F9	Cr9Mo1	-29/593	High sulfur oxidizing medium
Martensitic stainless steel
A217 CA15	A182 F6a	Cr9Mo1	-29/593	High sulfur oxidizing medium
Austenitic stainless steel（C≤0.08）
A351 CF8	A182 F304	0Cr18Ni9	-196/537	corrosive medium
A351 CF3	A182 F304L		-196/425	corrosive medium
A351 CF8M	A182 F316	0Cr18Ni12Mo2Ti	-196/537	corrosive medium
A351 CF3M	A182 F316L		-196/425	corrosive medium
low carbon Austenitic stainless steel（C≤0.03）
A351 CF3	A182 F304L	00Cr18Ni10	-0.459016393	corrosive medium
A351 CF3M	A182 F316L	00Cr18Ni14Mo2	-196/454	corrosive medium
Special alloy
A351 CN7M	B462Gr.NO8020 (ALLOY20)		-29/149	Oxidizing medium and various concentrations of sulfuric acid
A494 M-30C (Monel alloy)	B4564 Gr.NO4400		-29/482	Hydrofluoric acid, Sea water
Hastelloy H.B H.C				Strong corrosive medium such as dilute sulfuric acid

Notes:
1. Forged valve body material is dense, not easy to have defects, the structure size is not limited by the mold, and the pressure bearing performance is reliable. It is mostly used for high pressure, oxygen working conditions, small diameter or other small batch valve manufacturing, generally at high temperature, Choose forgings under high pressure or low temperature or special medium; castings are generally only suitable for medium and low pressure, and are mostly used for mass production of standardized molded valves.

2. The difference between material A351 CF3M and A182 F316L: the materials corresponding to the two standards are 316 stainless steel. CF3M stands for castings and is often used as valve material. The corresponding forging steel code is A182 F316L. ASTM A216 WCB is a casting, and its forging is A105; the casting of SS304 is A351-CF8, and the forging is A182-F304.

Valve actuator / actuation -(8)- application areas

August 19, 2020

Application areas of valve actuators:
Electric actuators are mainly used in the following three areas:
1. Power plant
Typical applications are:
① Application in thermal power industry
Air blower damper damper, Primary air intake damper, Air preheat damper damper, Flue gas recirculation, Bypass

electric actuator for butterfly valve

damper damper, Secondary air intake damper, Main bellows damper damper, Burner adjustment lever, Burner swing drive, Hydraulic push rod drive, Impeller Machine speed control, flue gas control valve steam, control valve, ball valve and butterfly valve, control sliding gate
②Valve actuator applications in other power industries
Ball valve dust control water jet impeller speed control control large hydraulic valve gas control valve burner ignition start steam control valve condensate recirculation, deaerator, boiler feed water, superheat controller, reheat thermostat controller, and other related valve applications
2. Process control
Used in the production process control of chemical, petrochemical, mold, food, medicine, packaging and other industries, according to established logic instructions or computer programs to accurately position, start and stop valves, tools, pipes, baffles, chutes, platforms, etc. , Opening and closing, rotation, use the temperature, pressure, flow, size, radiation, brightness, chromaticity, roughness, density and other real-time parameters detected by the system to adjust the system to realize the control of intermittent, continuous and cyclic processing .
3. Industrial automation
It is used in a wide range of aviation, aerospace, military, machinery, metallurgy, mining, transportation, building materials, etc., to adjust and control the movement points (moving parts) of various automation equipment and systems.
Examples of main applications in process control and industrial automation are as follows:
① Application in the production of sulphur ore
Water injection flow control ball valve and butterfly valve control
②Application of Potassium Carbonate Pipeline Valve Actuator
Sliding gate diverter Gate ball valve and butterfly valve Ball control valve
③Application of water treatment valve actuator
Liquid flow control, pressure regulator pressure control, acid solution flow control
④Application of valve actuator in limestone/cement plant
Ball or butterfly valve controls the treatment of dry cement, gypsum, or liquid. Air supply and induced draft fan adjustable damper damper bypass damper damper Environmental pollution control and dust removal device sliding door to control the logistics of raw materials in hoppers and storage gates control raw materials in The gas control valve at the feed port adjusts the intake air volume of the burner on the converter. The steam control valve controls the steam required for the production process.
⑤Application of actuators in grain processing plants
Gate Diverter valve Distributor Material unloader/heater Dust removal isolation baffle Air flow control (logistics drying) Ball valve and butterfly valve control
⑥Application of damper and valve actuator in steel mill
Ball or butterfly valve controls, the control of cooling water, wastewater, or other cooling media. Adjustable damper baffle air supply and induced draft fan bypass damper damper, gate Environmental pollution control and dust removal device, Sliding door controls, the flow of raw materials at the inlet to the hopper ,The raw materials in the storage warehouse are subject to logistics control, gas control valve, steam control valve, adjustment of the burner on the converter, and control of the steam required for the production process
⑦The application of damper and valve actuator in aluminum factory
Air blower damper damper, Primary air intake damper, Air preheat damper damper, Flue gas recirculation, Bypass damper damper, Secondary air intake damper, Main bellows damper damper, Burner adjustment lever, Burner swing drive, Hydraulic push rod drive, Impeller Machine speed control flue gas control, valve steam, control valve ball valve, and butterfly valve control, sliding gate
⑧Application of process control baffle
Air replenishment Exhaust fan bypass Hot/cold air mixing Emergency shutdown
⑨Application in petroleum industry
Oil injection process flow control Gas lift pipeline main valve pressure control Water injection process flow control Oil well oil quality sampling test / production valve
⑩Application in natural gas production and transportation industry
Gas lift airflow flow control, Gas pipeline main valve pressure control, Compressor surge control, Natural gas pressure control, Natural gas pipeline main valve pressure control, Emergency shutdown, Natural gas pressure regulator control, Pressure control, Compressor surge control, Flow control

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve actuator / actuation -(7)- generator

August 19, 2020

Generator for valve actuator:
1. The development history of generator controller The automatic control of generator set has experienced relay control. Greatly simplified the control circuit? Reliability has also been improved, to the point of more humanity,

electric actuator for butterfly valve

there are also some generator manufacturers produce small gasoline engine integrated machine, practical and convenient.

2. Diesel generator set structure Diesel generator set is generally composed of three parts: engine, generator and controller. The generator powered by the engine converts the mechanical energy of the engine into electrical energy. The controller is the brain part of the generator set. It not only provides engine start-up, shutdown, data measurement, data display and fault protection functions, but also provides generator power measurement, power display and power protection functions.

3. (i.e. only provide start-up, shutdown and high water temperature, low oil pressure, overspeed protection? Does not provide power display? Water temperature meter, oil pressure meter, hour meter, battery voltmeter, AC voltmeter, AC Ammeter and other instruments), standard type (providing power display, providing protection function? Without communication interface), high-end type (in addition to providing standard functions, but also providing communication interface? Remote control, remote measurement, remote signaling functions are available, some It also has a network interface? It can be monitored through the Internet? Some have a text message function, which is more suitable for unattended computer rooms in remote areas).

Fourth, the inspection steps of the diesel generator set test machine when purchasing diesel generator sets? The customer is most concerned about the price of the generator set? There are many kinds of generator sets according to the brand? And the price of the generator set with different diesel engine power is different , Diesel generator set manufacturers will introduce to you how to compare the prices of diesel generator sets.

One question: Ask about the purchase time of the old diesel engine, ask about the repairs in the past? Which main parts have been replaced? Ask what are the problems in use? In order to have a more comprehensive and systematic understanding of the old diesel engine.

Second look: look at the signs and appearance of the old diesel engine. See which factory produced it? When did it leave the factory? How long did it take? See if the paint on the exterior is peeling off? Is there any defect? Whether the model is eliminated, etc. Judge the degree of newness of the old diesel engine from the label and appearance.

Three trials: Test machine. Check the old diesel engine carefully by shaking the crankshaft, turning the flywheel, starting the machine, etc. Test machine is a very important step? The specific inspection steps are as follows:

1. Rotate the crankshaft to supply oil from the fuel injector. If the fuel injector makes a crisp sound? It means that the performance of the fuel injector and plunger pair is still good. If there is no abnormal noise such as “whipping” in the wheel chamber, it means that the gear wear is not serious.

2. Pull up and down to fly, if there is no noise, it means that the gap between the crankshaft main shaft and the bearing bush is not large.

3. Turn the flywheel so that the piston approaches the bottom dead center? Then shake the flywheel left and right? If there is no “click” sound, it means that the wear between the connecting rod shaft and the bushing is not serious.

4. Decompress the cylinder and sway the crankshaft. When decompression is removed, if the rebound force of the piston is large, the flywheel rotates rapidly, indicating that the degree of wear of the cylinder, piston, and piston ring is small. When cranking the crankshaft, the pointer of the oil pressure gauge should be no less than 1 or the red mark of the oil instruction can rise quickly, and the hand pressure should be laborious.

5. Start the machine, if it is easy to start? The smoke is colorless or light gray? The speed is stable and no noise? It shows that the technical condition of the old diesel engine is good. Remarks: During the testing process of diesel generator set, it is best to operate and track changes in data such as air pressure and oil pressure in the diesel generator controller. Therefore, the stability of the quality of the diesel generator controller has high requirements in terms of humanization and other aspects. This controller is highly evaluated in the market.

6. How to buy diesel generator sets What issues should companies pay attention to when purchasing diesel generator sets? Diesel generator sets are widely used in telecommunications, financial and financial departments, hospitals, schools, commerce and other departments, industrial and mining enterprises and other special purpose independent power supply. Enterprises must have their own standards when purchasing diesel generator sets.

1. The performance and quality of the diesel generator set to be purchased must meet the requirements of relevant standards. The diesel generator set for communication must meet the requirements of the G3 or G4 level in GB2820-1997? At the same time as the “Communication diesel generator set into the network The 24 performance index requirements stipulated in the Implementation Rules for Quality Certification and Testing? At the same time, it must pass the strict inspection of the Communication Power Equipment Quality Supervision and Inspection Center established by the Chinese industry authority. The purchase of diesel generator sets for military communications must meet the relevant GB2820-1997, GJB related standards and the provisions of the “Quality Inspection Standards for Communication Power Equipment” formulated by relevant military departments, and must pass the strict inspection of the equipment quality by the organization department.
2. The main factors that should be considered when purchasing diesel generator sets. The main factors that should be considered when purchasing diesel generator sets are mechanical and electrical performance, the purpose of the unit, the capacity and range of load changes, and automation functions.

1. The purpose of diesel generator set. Because diesel generator sets can be used in three situations: common use, standby and emergency. Therefore, different applications have different requirements for diesel generator sets.
2. Load capacity of diesel generator set. The load capacity and load variation range should be selected according to different uses. Determine the single engine capacity of the diesel generator set and the capacity of the standby diesel generator set.
3. Environmental conditions for the use of diesel generator sets. Mainly refers to altitude and climatic conditions.
4. Selection of diesel generator set
5. Pay attention to generator and excitation mode when purchasing diesel generator set
6. Selection of the automation function of diesel generator set

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve actuator / actuation -(6)-Control panel

August 19, 2020

Control panel of valve actuator:
The main purpose of the control panel is to distribute the electrical energy output by the generator to the user’s load or electrical equipment, and it is also used to indicate the operation of the diesel generator and to keep the

electric actuator for valve

generator’s voltage stable when the load changes. Generally, voltmeters, frequency meters, ammeters, power meters, three-phase current conversion switches, three-phase voltage conversion switches, voltage setting knobs and various indicators are installed on the control panel. For the oil pressure gauge, oil temperature gauge, battery charging ammeter, water temperature gauge, start button and starter electric lock, some of them are directly installed on the control panel according to the design requirements, and some are installed on the dashboard of the diesel engine. The components installed inside the control panel are mainly related to the excitation mode of the generator and the automatic control of the diesel engine. The internal structure of the diesel generator set control panel.

Simple control panels are generally equipped with voltage regulators, silicon rectifier diodes, varistors, automatic air switches, current transformers and other components. More complex control panels must also install overload and short-circuit protection devices, electronic speed regulators, and other components. SCRs, relays, various safety devices and electrical equipment such as small transformers.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve actuator / actuation -(5)- advantages

August 19, 2020

Advantages of valve actuators:
Actuator companies can establish a complete, efficient, flexible, and integrated marketing information platform

pneumatic actuator for marine valve

through the application of the CRM system, achieve the following goals, and help companies gain advantages in the fierce market competition:

1. Comprehensive and effective management of customer information resources and market competition information;
2. Master every detail of sales opportunities, procurement, sales, contracts, expenses, services, care, etc. throughout the process;
3. Comprehensive and multi-angle analysis of customers, sales and accounts receivable provide a basis for decision-making;
4. Brand-new service and care management thought runs through pre-sales, in-sales and after-sales;
5. All employees realize collaborative office, information release and sharing, and centralized document management
6. The customer relationship management system can enable sales staff to manage customers conveniently and quickly, and record customer information in detail, eliminating the trouble of finding traditional notebooks every day; the system will remind sales staff to do what they should do today; at the same time You can easily determine the type of customers, facilitate the tracking of important customers, and improve work efficiency.
ductile iron, DI, butterfly valve, manufacturer, center line, TH valve
7. The sales staff management system can record sales staff contact business records and event records, and record the whole sales process in detail, which is convenient for the enterprise to grasp all the information of customers. At the same time, the leader can guide the sales staff’s sales process at any time, adjust sales in time, and promote sales. Achieve unified management of sales personnel in all sales outlets, which facilitates the leadership to conduct employee assessment, and at the same time ensures that customer information will not be lost due to employee resignation.
8. The customer service management system can record and track the work of the customer service department throughout the whole process, and the customer service staff can realize task transfer and coordination through the system. Through the system, the customer service departments of all parts of the company can coordinate the tasks organically. Even in different places, they can also accept tasks and achieve collaboration in the shortest time, realizing the promise of “service in place within 24 hours”.

The above briefly analyzes several typical aspects of actuator CRM applications. When facing the production material market or the living material market, the manufacturing of systems/equipment/components, finished products/rough processed products, medicines/food/beverages, durable goods/quick consumables, etc. Products, adaptive business models are different, and the strategies and methods adopted are also different. If your business belongs to the manufacturing industry, if your business organization (sales, service, marketing) implements CRM management.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve actuator / actuation -(4)-angle stroke valve actuator application

August 19, 2020

Angle stroke valve actuator application products:

1. Butterfly valve:
The baffle of the butterfly valve controls the flow of fluid with the rotation of the shaft. It is composed of valve body, baffle, baffle shaft and shaft seal. Its simple structure, small size, light weight, low cost and large flow capacity are especially suitable for occasions with low pressure difference, large diameter, large flow gas and fluid with su

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

spended solids, but the leakage is large. Its flow characteristics are achieved at the corners. The front and equal percentage characteristics are similar, but the work will be unstable and the characteristics will not be good in the future; use in the corner range. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also used in cooling water systems of thermal power stations.

2. Ball valve:
The ball valve is defined in the standard GB/T21465-2008 “Valve Terminology” as a valve in which the opening and

closing part (sphere) is driven by the valve stem and rotates around the axis of the valve stem. The ball valve has a 90-degree rotation. The cock body It is a sphere with a circular through hole or channel passing through its axis. It is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid adjustment and control. Among them, the hard-sealed V-shaped ball valve has a strong shear between the V-shaped core and the metal seat of the hard alloy. Shearing force is especially suitable for media containing fibers and tiny solid particles. The multi-way ball valve can not only flexibly control the confluence, divergence, and flow direction switching of the

14 ball-valve-6

medium in the pipeline, but also close any channel and connect the other two channels. This type of valve should generally be installed horizontally in the pipeline. Ball valve classification: pneumatic ball valve, electric ball valve, manual ball valve. The ball valve can be closed tightly with only a 90-degree rotation and a small torque. The ball valve is most suitable for use as a switch and shut-off valve, V-shaped ball valve. In the developed western countries, the use of ball valves is increasing year by year. In our country, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electric power, municipal administration, steel and other industries. Occupy a pivotal position in the national economy.

3. Cam flex valve:

Cam flex valve, also known as eccentric rotary valve, is also a new-type regulating valve. The center line of the spherical valve core deviates from the center of the rotating shaft, and the rotating shaft drives the valve core to rotate eccentrically, so that the valve core enters the valve seat forward and downward.

The eccentric rotary valve has the advantages of small size, light weight, reliable use, convenient maintenance, strong versatility, and low fluid resistance. It is suitable for occasions with high viscosity and has good performance in lime, mud and other fluids.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Valve actuator / actuation -(3)-classifications

August 19, 2020

Double acting valve actuator:
The selection of double-acting actuators takes DA series pneumatic actuators as an example. The output torque of

Pneumatic actuator (2)

the gear-and-pinion actuator is the piston pressure (supplied by the air source pressure) multiplied by the pitch circle radius (arm). And the friction resistance is small and the efficiency is high. The output torque is linear when rotating clockwise and counterclockwise. Under normal operating conditions, the recommended safety factor for double-acting actuators is 25-50%

Single-acting valve actuator:
The selection of single-acting actuator takes the SR series pneumatic actuator as an example. In the application of spring return, the output torque is obtained during two different operations. According to the stroke position, each operation produces two different torque values. The output torque of the spring-return actuator is obtained by multiplying the force (air pressure or spring force) by the force arm. The first situation: the output torque is obtained by air pressure entering the central cavity to compress the spring, which is called “air stroke output torque”. In this case, the air source pressure forces the piston to turn from 0 degrees to 90 degrees. Due to the reaction force generated by the compression of the spring, the torque gradually decreases from the maximum value

hydraulic actuator for marine valve

at the starting point to the second condition: the output torque is the spring recovery when the middle cavity loses air. The force acting on the piston is called “spring stroke output torque”. In this case, due to the extension of the spring, the output torque gradually decreases from 90 degrees to 0 degrees. As mentioned above, the single-acting actuator is based on two It is designed on the basis of generating a balance torque under this condition.

Linear valve actuator:
1. Through single seat valve

The so-called single seat means that there is only one valve core and one valve seat in the valve body. Its characteristics are simple structure, small leakage (even completely cut off) and small allowable pressure difference. Therefore, it is suitable for occasions requiring clean media with small leakage and small working pressure difference. Special attention should be paid to the allowable pressure difference in the application to prevent the valve from closing.

2. Straight through double seat valve

There are two valve cores and valve seats in the valve body of the straight-through double-seat regulating valve. Compared with the single seat valve of the same caliber, its flow capacity is about 20% to 25% larger. Because the force of the fluid on the upper and lower valve cores can cancel each other, but the upper and lower valve cores are not easy to close at the same time, the double seat valve has the characteristics of large allowable pressure difference and large leakage. Therefore, it is suitable for clean media where the pressure difference between the two ends of the valve is large and the leakage requirement is not high. It is not suitable for high viscosity and fiber-containing occasions.

3. Angle valve

The valve body of the angle control valve is right-angled, its flow path is simple, and the service force is small. It is suitable for the control of high pressure difference, high viscosity, suspended solids and granular materials. Generally used for bottom inlet and side outlet, this kind of control valve has better stability. In high pressure situations, in order to prolong the service life of the spool, the side inlet and the bottom outlet can be used, but oscillation is prone to occur in small openings.

Valve actuator / actuation -(2)-classification and working principle

August 19, 2020

Classification of valve actuators:
(1) According to the driving energy used, the actuator is divided into three types: pneumatic, electric and hydraulic actuators.
(2) According to the form of output displacement, the actuator has two types: angle type and linear type.

Pneumatic actuator (2)

(3) According to the law of action, actuators can be divided into three types: switch type, integral type and proportional type.
(4) According to the input control signal, the actuator can be divided into several types, such as air pressure signal, direct current signal, electric contact on-off signal, pulse signal, etc.

The working principle of valve actuator:
In the gear stage, the engine speed can be transmitted to the output rod through two sets of gears. The main reducer is completed by planetary gears, and the auxiliary reducer is realized by worm gears, which are fixed in the center by a set of tight springs. In the event of an overload, that is, when the output rod exceeds the set torque of the spring, the central worm gear will undergo axial displacement, and the switches and

electric actuator for valve

signal devices will be fine-tuned to provide protection for the system. The output rod is coupled with the worm gear when the engine is working, and is coupled with the hand wheel when it is manually operated, under the action of the coupling operated by the external change control lever. When the engine is not working, the motor drive can be easily cut off, and the handwheel can be connected by simply pressing the lever. Since the motor drive takes

precedence over manual operation, when the engine restarts, the reverse action will automatically occur. This can avoid turning on the hand wheel when the engine is running, which is beneficial to protect the system.

Since the hand wheel is directly coupled with the output rod, it can ensure the normal manual operation of the valve when the internal gear fails or is damaged.

The switch and signal device installed on the gear is a sealed shell, which protects its internal components to achieve

hydraulic actuator for marine valve

the following functions:

Local or remote display of valve position
Actuator/valve overload protection
Limit valve stroke range
Electrical interface

The installation of valve actuators on different types of valves is completed by the output rod, which can be applied to various existing valve rod configurations.

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