The Pressure Seal Gate Valve is a member of the multi-turn valve family and one of the most commonly used valve types in a host of industries. They consist of a round, flat disc, or gate, which is attached to a threaded lead screw type valve stem. At the bottom of its travel, the disc closes off the flow of fluid through the valve chamber. When the valve stem is turned, the valve gate rises to open the flow path.A flanged gate valve is a specific type that includes a pair of flange discs, one on either end of the valve body. These are typically round plates that are open at their centers cast as integral parts of the valve body. The discs are drilled with a row of holes located around their circumference that are used to mount the valve. These discs allow the flanged gate valve to be mounted onto existing flanges in standardized pipe systems. If, however, the valve needs to be mounted on a non-standardized flange, a range of adapters are available which will facilitate the installation.
1 Shut off the water before the Slab Gate Valve by closing a valve upstream of it. You may have to close the main water valve to the home if there is not another option. If it is your main water valve that needs repairing, you will need to contact the city to turn off the water at the street. Open a valve downstream of the gate valve to remove the pressure from the pipes.
2 Remove the turning mechanism from the gate valve with the appropriate tools. Most turning mechanisms will be secured by a single slotted screw in the center of the handle. Loosen this screw to remove the turning mechanism.
3 Remove the retaining nut from the top of the gate and then remove the gate from the valve by turning it counter-clockwise. Examine the gates stem washer for evidence of damage. If the stem washer is damaged, replace it with a new part from the hardware store.
4 Remove the gate valves seat with a seat removal tool. The seat removal tool maybe specific to your faucet. Examine the valves seat for evidence of damage. If the seat is not smooth or uniform replace it with a new seat.
5 Reassemble the faucet the same way you to took it apart. Test it by turning on the water supply.
The article comes from Gate Valve.
Repair A Pressure Seal Gate Valve
Polish Top Entry Ball Valve
The ball valve was invented in 1950s. It is also one of the fast-developed valves in recent years, especially in USA, German, Japan, France, Italy, Spain and UK where Trunnion Mounted Ball Valve are widely used. The types and quantities of ball valve is still increasing at speed, and its engineering development starts to move towards applications of high temperature, high pressure, large port, secure sealing, longer duration, great adjustment and multiple functions. Due to dedication to research and development, the stability and capability of ball valve managed to reach the higher level of achievement, which is able to take place of gate valves, check valves and throttle valves in applications. Ball valves are widely used in aerospace, petrochemical, pipelines, food and beverage and construction.
1 Remove the ball valve’s two upper studs. After you locate the upper and lower studs on the valve, remove the two nuts that are on the two upper studs with an adjustable wrench. Take out the two upper studs, and set them aside.
2 Loosen the two nuts that are on the lower studs.
3 Separate the body assembly to access the Top Entry Ball Valve internal parts.
4 Remove the upper nut and the lower nut. After you remove the upper nut that secures the valve handle, take off the handle. Then remove the lower nut.
5 Pull the threaded bolt out of the ball.
6 Slide the ball out of the enclosure.
7 Polish or clean the ball. Wiping it with a clean cloth or rag removes residue that is on the ball.
8 Reassemble the ball valve. Set the ball back in the enclosure. Insert the threaded bolt back into the ball. Tighten the lower nut, and then set the handle back in place. Tighten the upper nut to secure the handle. Attach the two body sections together. Insert the upper studs into the assembly. Tighten the upper nuts and the lower nuts to finish reassembly.
The article omes from Ball Valve.
Pressure Seal Globe Valve Features
A Pressure Seal Globe Valve is a somewhat simplistic design but is crucial to modern plumbing and manufacturing. In use for more than 139 years, the globe valve was originally designed to help with the newly invented steam engine. The globe valve design is so efficient its remains a mainstay in pluming and industry here in the 21st century.
(1) structure is more simple than gate valves, manufacture and repair is more convenient.
(2) sealing surface not easy wear and scratches, , good sealing, there is no relative sliding between disc and body when open, so wear and bruises are not serious, sealed performance is good, long service life.
(3)when close and open, disc trip is short, thus the height of cut-off Actuated Globe Valve is smaller than gate valves, but length of structure is longer than gate valves.
(4) moment is large, on and off is arduous, on-off time longer.
(5) fluid resistance is great, because body medium channel is tortuous, fluid resistance is large, power consumption is large.
(6) medium flow direction when nominal pressure PN≤16MPa, generally USES downstream from disc bottom to upper, when The nominal pressurePN≥20Mpa, generally USES back flow, medium from the upper of the disc to the down. To increase the sealing performance. When using, globe valves medium only single direction, medium can not change flow direction.
(7) when full open disc often affected by erosion.
The article comes from Knife Gate Valve.
Forged Steel Gate Valve Trim Types
We have all seen Forged Steel Gate Valve–although few people know the proper name for them. In large buildings, factories, and in many other places where there are pipes or ducts there is sometimes a round handle on a bulbous section of the pipe. The obvious use for this handle is to control the flow of whatever is going through the pipe or duct. These are gate valves.
Discs
Gate valve discs come in two different designs: parallel and tapered. They are the trim element that actually stops the fluid flow. Basically, these two types are differentiated by the way in which they lock onto the walls of the valve. They both operate by sliding into specially designed slots. Tapered discs are placed at an angle. Valves with tapered discs are also called wedge gates, and come in three sub-types: solid wedge, flexible wedge and split wedge.
Stem
The stem of the Cryogenic Gate Valve is the part that connects the handle and the disc. Stems come in three different designs, inside screw, rising stem (ISRS), non-rising stem (NRS) and outside screw and yoke (OS&Y). ISRS stems are the most commonly used in bronze valves. NRS valves where there is not much space above the handwheel, and OS&Y stems are the most common type of industrial valve.
Disc Seating Area
The disc seating area are the slots into which the disc fits in order to stop the flow of fluid. Disc seating areas come in different types depending upon the sort of disc mechanism they are working in tandem with. For instance, the disc seating area for a tapered disc rests at the same angle in which the disc itself must sit.
Standard Gate Valve Trim
Standard gate valve trim is rated to handle temperatures of between 0 and 250 degrees Fahrenheit. They are commonly used in wellheads, manifolds and flowlines.
Stainless Gate Valve Trim
Stainless trim is rated for the same duty as standard trim, but is resistant to corrosion, especially applications with a high level of carbon dioxide pressure.
Sour Gas and Oil gate Valve Trim
Sour gas and oil Knife Gate Valve trim is used when the system must have a high resistance to hydrogen sulfide. Hydrogen sulfide can make some materials very brittle. Most often, this trim rests on pipes that are used for oil and gas, but can also quite often be used for other chemicals.
The Way To Reduce Cryogenic Gate Valve
A Cryogenic Gate Valve uses a flat plastic or metal blade, called the gate, that slides up and down into a slot, known as the seat, that is cast into the valve body. The gate is attached to a threaded stem and handle that raises and lowers the gate. When lowered, the gate wedges itself into the valve seat, cutting off the flow of water. When the gate is raised, water flows through the valve. Some gate valve designs feature a gate hole in the blade that is lowered into the fluid path to allow flow and raised to cut off flow.
The Way To Reduce Gate Valve
1 Turn off or kill the fluid source up the line from the Pressure Seal Gate Valve you want to reduce. Preferably, this would be at another gate valve. If possible, open the down line release and drain the fluid from the pipe.
2 Detach the down line side of the gate valve from the existing pipe with the pipe wrench. Remove the flange bolts if the gate valve is flanged or unscrew the collar if the valve is threaded.
3 Attach the reducer down line of the gate valve. Beforehand, cover the pipe threads with Teflon tape, if the gate valve is threaded. If it is flanged, cover the flange gasket with silicone.
4 Attach the replacement pipe to the reducer.
The article comes from Gate Valve.
Variation Of Ball Valve
Ball valves are used to turn liquid and gas flows fully on and off with only a quarter turn of a ported ball within the Wafer Ball Valve from a handle or powered actuator. Ball valves are found in every shutoff valve application, with plastic versions of one inch size and less being available for domestic service for a few dollars all the way to industrial models several feet in diameter made from exotic metals costing tens of thousands of dollars.
Ball valves consist of a smooth shiny metallic or plastic ball locked in a smooth cavity with a ring shaped seal on either side of the ball concentric with the entry and exit ports of the valve. The ball has open bore or port through the middle of the ball in only one direction. A handle is connected through the side of the Cryogenic Ball Valve to the ball with a sealed valve stem shaft. When the valve is off, the port is perpendicular to the pipeline containing the valve, and flow is completely blocked.
The ball valve comes in several variations. The full port valve has a hole in the ball that is the same dimensions as the pipe that it is attached to. This keeps water from being restricted as it flows. The reduced port valve creates an opening in the ball that is smaller than the pipe. This creates less water flow. A trunnion valve has a pin securing the ball so that it doesn’t dislodge. This is for high velocity flow. There are three- and four-way valves, as well. With these the flow is altered by the position of the ball. The hole in the ball of the Ball Valve is normally shaped like a T or L. When it is a T it can allow flow in two directions at once or one direction with the other side closed. When it is an L shape it allows flow in only one direction at a time.
Replace A Actuated Forged Steel Gate Valve
The main cutoff valve for the water line entering most homes is a Actuated Gate Valve. These are simple valves with a swing handle type of control. When the handle is aligned with the pipe, the water is on. When the handle is perpendicular to the pipe, the water is off. While these valves tend to be durable, some of them will need to be replaced as they age or when new water pipes are installed.
1 Shut off the water main for the house. The water main is usually located where the main water line from the street enters the home.
2 Turn on a faucet at the highest level in the building and one at the lowest level to allow the water to drain from the lines.
3 Unscrew the water supply hose connected to the shutoff Forged Steel Gate Valve being replaced using an adjustable wrench and by turning it counterclockwise.
4 Cut off the old valve from the water line as close to the base of the valve as you can using a hacksaw. Make the cut at a 90-degree angle to create a square cutoff.
5 Sand the end of the water line with emery paper to remove any burrs and roughness.
6 Place the larger nut that came with the ball valve onto the water line with the threads pointing toward the end of the line. Slide the compression ring that came with the ball valve onto the end of the water line. Fit the compression ring no more than 1/2 inch onto the line.
7 Wrap the threads on the shutoff valve with Teflon tape to help seal the connection.
8 Fit the larger end of the ball valve onto the water line and bring the nut forward. Thread the nut onto the threads of the ball Gate Valve by hand to get them started. Tighten the nut with an adjustable wrench while holding the water line securely with a pair of slip-joint pliers. Restore the water supply a small amount at a time to bring up the pressure slowly.
Piston Check Valve Operation
Check valves are devices that are installed in pipelines in order to stop the backflow of material. In many cases, the material flowing through the pipe is water, and the check valve keeps the water from flowing backwards in the pipe. They do not require any outside activation, but are rather designed with mechanisms that block the water from reversing direction at a certain point.the article comes from Knife Gate Valve
Operation of a Check Valve
There are several different types of check valves. A ball Piston Check Valve consists of a ball that sits over the valve’s opening. When liquid flows past the ball, it pushes the ball away from the mouth of the valve, which gives it room to flow through the pipe. When the liquid begins to flow the other way, however, the ball fits tightly over the valve opening, essentially plugging it.
Most valves work in a similar way, although they may not contain balls. For example, swing Pressure Seal Check Valve contain a swinging door on hinges that blocks backward-moving material, and split disk check valves contain a folded metal disk that springs open when the material moves backwards.
How Does A Floating Ball Valve Work?
A Floating Ball Valve is a valve with its ball floating (not fixed by a trunnion) inside the valve body, it drifts toward to the downstream side and tightly pushes against the seat under the medium pressure to ensure sealing reliability. The floating ball valve has simple structure, good sealing performance but the seat material is required to withstand the workload since the sealing pressure is bared by the seat ring. Due to unavailability of high performance seat material, floating ball valve is mainly used in middle or low pressure application.
The Floating Ball Valve is used in a reserve water tank and has three primary parts: the Stainless Steel Ball Valve, the stem and the float device. The valve will block the flow of water through the pipe as the stem rises and creates a tight seal. The stem connects the valve to the float device. In some applications the stem is also used to adjust when the water flow will be blocked. The float device is normally round and filled with air. This device is air tight and is attached to the stem. Due to the trapped air in the float device it has buoyancy and will float atop the water. When the water is released from the reserve the float device drops, opening the valve. The valve will remain open until the float device is raised to a pre-determined level by the rising water. The valve will then be closed and the water supply shut off.
The article comes from Ball Valve.
Cryogenic Gate Valve Design And Features
Cryogenic Gate Valve Design
Applications such as liquefied natural gas and other low temperature fluids, present special extreme temperature valve functionality challenges. Valves designed for cryogenic services, are specially prepared and designed to overcome these challenges. Appropriate component materials such as 304SS (CF8) and 316SS (CF8M) are normally used for body and trim, offering superior impact strength, and excellent corrosion resistance and heat loss properties. An extended bonnet and gas column design is also normally adopted to provide thermal insulation at the stem seal and stem packing area. At sufficient length, this design feature places the functionality of the stem seal in the vapor zone of the liquid media providing safe and continuous valve operation. A variety of body, trim, seat, and seal materials are available for use in cryogenic service. Customer specified options, such as body cavity vent hole, special extension lengths, and materials are also available upon request.
Cryogenic Gate Valve Features:
Low Temperatures to -321°F(-196°C)
Extended Bonnet
Pressure release holes
Materials subzero treatment
ASME B16.34
The article comes from Cryogenic Gate Valve.New design Cryogenic Gate Valve – Cryogenic Gate Valve manufacturer in China, also offer Cryogenic Gate Valve, China Cryogenic Gate Valve, Cryogenic Gate Valve Wholesale, Gate Valve, China Gate Valve, Gate Valve Wholesale OEM Service.
