types of gate valve Archives

Gate valve has a broad market in the field of sewage treatment

October 11, 2021

The market situation is often complementary to the country’s development policies. As the country implements energy conservation and emission reduction strategies and accelerates the cultivation and development of strategic emerging industries, the construction scale and service scope of my country’s sewage treatment industry have

Socket welding gate valve-DN150-PN16-square hat (1)

gradually expanded. For gate valve products that are indispensable in the field of sewage treatment, it has entered a period of rapid development. The market demand for Tanghai gate valve products is increasing day by day, and it has a broad market space in the sewage treatment market.
Through the data feedback of Tanghai Valve Business Department, we can see that in addition to gate valves, butterfly valves, ball valves and other products are also popular valve products by customers, which play an important role in sewage treatment and are in strong demand. At present, the rate of urbanization in my country is continuously increasing, and the amount of water supplied by water plants and the scale of sewage treatment in sewage treatment plants are gradually increasing. Therefore, sewage treatment requires a large number of environmentally friendly valve equipment.
Although gate valve products are in great demand, domestic gate valve manufacturers have mixed good and bad products. Some valve manufacturers have poor product quality, low technical level, narrow export categories, varieties and regions, and are not competitive in the international market. But for veteran manufacturers like Tanghai Valve, challenges and opportunities coexist. On the one hand, competition in the valve market has become more fierce. Common gate valves, ball valves, globe valves and other product markets have begun to fight fierce price wars. This is a huge challenge for Tang Hai. On the other hand, market competition encourages the old valve manufacturers represented by Tanghai Valve to accelerate the integration of their products with international standards, enhance the competitiveness of enterprises and regions, promote the quality improvement and transformation and upgrading of gate valves and other valves, and realize the sustainable development of the valve industry.
On the road in the future, Tanghai Valve will open up more sales channels and increase effective production capacity for the application of gate valve products in the field of sewage treatment, so as to obtain more orders. Through the correct analysis of manufacturing, marketing, expansion, financial and other costs, effective cost control is achieved, and the company adheres to the sound development path that guides the enterprise toward environmental protection.

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

Difference between NRS gate valve and RS gate valve

August 11, 2021

NRS gate valve, means Non-rising Stem gate valve; RS gate valve, means Rising stem gate valve. you can see the difference in appearance on below photos.

Gate valve is one of the most common valves in piping systems. Because it can only be fully open and fully open, gate valves are commonly used when the fluid medium in the pipeline needs to be cut off. The operation of the gate valve does not need to be so frequent. Gate valves are widely used because they can be divided into many types. Different gate valve types have certain differences in use. This article mainly analyzes the difference between the RS gate valve and the NRS gate valve.

rising stem gate valve-RS-BB OS&Y (3)

Gate valves are classified according to the type of stem, which can be divided into two types: RS gate valve and NRS gate valve. The two are different in transmission mode, valve body structure, installation space, application range, etc.
1. The difference in the transmission mode. The transmission mode of the RS gate valve is that the handwheel drives the nut to rotate in place, and the valve stem rises and falls linearly. Through the threaded drive of the valve stem and the steering wheel, the valve flap is raised and lowered to complete the switch; the NRS gate valve is manual The wheel drives the valve stem to rotate. The hand wheel and the valve stem are connected together and relatively immovable. There are threads in the gate, and the valve stem rotates at a fixed point to drive the gate to rise and fall.
Second, the difference in structure, the structure of the rising stem gate valve is that the stem nut is on the bonnet or bracket. When the gate is opened and closed, the stem nut is rotated to realize the lifting of the stem. The structure of the NRS gate valve is that the stem nut is in the valve body and is in direct contact with the medium; when opening and closing the gate, it is realized by rotating the stem.

DIN-F4-BB-NRS-soft seated-wedge gate valve-DN100-PN16-copper holding ring-handwheel (3)

Third, the difference in installation space, the rising stem gate valve requires a larger installation space due to the stem; the height of the NRS gate valve is small, and it will not take up too much space during installation.
Fourth, the difference in application scope, the structure of the rising stem gate valve is beneficial to the lubrication of the stem, and the degree of opening and closing is obvious; the stem thread of the NRS stem gate valve is not only unable to be lubricated, but it is directly corroded by the medium and is easily damaged. Therefore, the RS gate valve is more The NRS stem gate valve has a wider range of applications.

The above is the difference between the RS gate valve and the NRS gate valve. Next, I will introduce you a little common sense, how to judge the RS gate valve and the NRS gate valve:

The stem of the RS gate valve drives the gate to move up and down together. The drive thread on the stem is outside the valve body. The opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the stem; the drive thread of the NRS gate valve is located on the valve. Inside the body, during the opening and closing process, the valve stem only rotates, the gate moves up and down in the valve body, and the valve opens and closes until the steering wheel does not rotate.

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

How many types of gate valves?

July 19, 2021

Types and classifications method of gate valves
Gate valve, also called slab valve, is mainly composed of valve body, bonnet, gate, valve stem, valve seat and sealing packing. It is one of the most common valve types in isolation valves. The main purpose of the gate valve is to cut off the fluid. For this reason, it is usually called a “cut off” valve or a “blocking” valve. There are many different structural forms of gate valves, and the types of sealing elements used in them are different. According to the

Socket ended resilient seated wedge gate valve-ductile iron (1)

structure of the sealing element, it can be divided into several different types.
Classified by valve stem:
According to the stem type, it can be divided into bright stem gate valve and dark stem gate valve. The valve stem is the operating part of the gate valve, and its function is to transmit the opening and closing force to the opening and closing parts.
1. The trapezoidal thread of the stem of the rising stem gate valve is placed outside the valve body and located on the upper part of the valve stem. By rotating the stem nut, the valve stem drives the gate plate to rise and fall synchronously to realize the opening and closing of the valve, so it is easy to identify the valve. Open and close state to avoid misoperation. Since the stem nut is outside the body cavity, it is conducive to lubrication, and the opening and closing state is intuitive and obvious, so it is widely used. However, in harsh environments, the exposed threads of the valve stem are susceptible to damage and corrosion, even affecting operation. Its disadvantage is that the height of the valve after opening is large, and a stroke is usually added to the original height of the valve, which requires a lot of operating space.
2. Dark stem gate valve is also called rotating stem gate valve (also called dark stem wedge gate valve). The stem nut is placed inside the valve body and is in direct contact with the medium. It is often fixed on the gate. Through the rotation of the valve stem, the valve stem nut drives the gate to move up and down to complete the opening and closing. Usually there is a trapezoidal thread at the bottom end of the valve stem. Through the thread at the bottom end of the valve and the guide groove on the valve disc, the rotary motion is changed into linear motion, that is, the operating torque is turned into operating thrust. Since the trapezoidal thread used for transmission is located inside the valve body, it is easily corroded by the medium and cannot be lubricated. The opening degree cannot be directly observed, and an indicating device is required. However, its valve stem does not move up and down, and requires a small operating space, so it is suitable for occasions with limited locations and dense pipelines.

gate valve (3)

Classified by structure:
According to the structure type, it can be divided into two types: wedge gate valve and parallel gate valve. That is, a wedge-type gate valve is called a wedge gate valve, and a parallel gate valve is a flat gate valve.
1. The flat gate valve means that the sealing surface is parallel to the vertical centerline, so the sealing surface of the valve body and the gate plate are also parallel to each other. The most common type of this kind of gate valve is the double gate type. In order to make the valve body and the two sealing surfaces of the gate closely contact when closed, a double-sided thrust wedge is often used between the two gates. Most of them are used on low-pressure pipelines such as small pipelines. Parallel gate valves using single gates are also rare but rare.
2. Wedge gate valve means that the sealing surface is at a certain angle to the vertical centerline, that is, the two sealing surfaces are wedge-shaped gate valves. The wedge gate valve has single and double gate plates. The advantage of the double gate type is that the accuracy of the sealing and the angle is lower, the temperature change is not easy to make the gate wedged, and the sealing surface wear can be compensated with gaskets. The disadvantage is that the structure is complex, and it is easy to stick in dry media, and the main reason is that the upper and lower baffles are easy to fall off after years of corrosion.
Classification by other methods:
According to different standards: national standard gate valve, American standard gate valve, German standard gate valve, Japanese standard gate valve
According to the connection method: flanged gate valve, welded gate valve, threaded gate valve (divided into internal thread and external thread)
According to pressure level: high pressure gate valve, low (medium) pressure gate valve According to driving mode: electric gate valve, pneumatic gate valve, manual gate valve
Classified by material: stainless steel gate valve, forged steel gate valve, cast steel gate valve, carbon steel gate valve, cast iron gate valve, copper gate valve (also divided into bronze gate valve, brass gate valve), ceramic gate valve, plastic gate valve

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

Classification and advantages of gate valve

August 13, 2020

Gate valve types:

There are many domestic manufacturers of gate valves, and most of the connection dimensions are not uniform.

gate valve (3)

Mainly divided into the following categories: 1. According to JB/T2203-1999 “Structural Length of Gate Valve”, the standard valve of the Ministry of Machinery; 2. According to GB/T12221-2005 “Metal Valve Structure Length”, the national standard valve; 3. According to American standard valves produced by ASME B16.10-2009 “Face-to-face and End-to-End Dimensions of Valves”.

Gate valves are divided into wedge type and parallel type according to the structure of the gate. There are 3 types of wedge gates: single gate, double gate and elastic gate.

Gate valves are divided into flat gate valves and knife gate valves according to their structure types.

The working principle of manual gate valve: Turn the hand wheel, and the valve plate connected with the valve stem can be lifted or lowered by the thread of the hand wheel and the valve stem to open and close.

According to the classification of shell/body material, gate valves can be divided into:

Metal material valves: such as carbon steel valves, alloy steel valves, stainless steel valves, cast iron valves, titanium alloy valves, Monel valves, copper alloy valves, lead alloy valves, etc.

Metal valve body lining valves: such as rubber-lined valves, fluorine-lined valves, lead-lined valves, plastic-lined valves, and enamel-lined valves.

Non-metallic materials valves: such as ceramic valves, glass valves, plastic valves.

Advantages of gate valve:
1. Small flow resistance. The medium channel inside the valve body is straight, the medium flows in a straight line, and the flow resistance is small.
2. Less effort when opening and closing. It is compared with the shut-off valve, because whether it is open or closed, the direction of movement of the gate is perpendicular to the direction of medium flow.
3. Large height and long opening and closing time. The opening and closing stroke of the gate is large, and the lifting is carried out by the screw.
4. Water hammer is not easy to produce. The reason is the long closing time.
5. The medium can flow in any direction on both sides, easy to install. Both sides of the gate valve channel are symmetrical.
6. The structural length (the distance between the two connecting end faces of the shell) is small.
7. Simple shape, short structure length, good manufacturing technology and wide application range.
8. Compact structure, good valve rigidity, smooth passage, small flow resistance, stainless steel and hard alloy sealing surface, long service life, PTFE packing, reliable sealing, light and flexible operation.

Disadvantages of gate valve:

It is easy to cause erosion and scratches between the sealing surfaces, and maintenance is difficult. The overall size is large, opening requires a certain amount of space, and the opening and closing time is long. The structure is more complicated.

Posts

Gate valve has a broad market in the field of sewage treatment

Difference between NRS gate valve and RS gate valve

How many types of gate valves?

Classification and advantages of gate valve

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