Valves and Sealing.com

Home  :  Submit your News  :  Advertise  :  Site Map  :  Contact Us




You are here: Home >


 
 
Gate Valves
 
 
v What is a gate valve ?
v Where can I find gate valve suppliers & gate valve manufacturers?
v Gate valve videos
v International standards related to gate valves
 
 
What is a gate valve ?
A gate valve is a valve primarily designed to be in fully open or closed position by lifting a gate or wedge out of the path of the fluid. It offers a straight flow path without any obstruction in the flow, resulting in a low pressure drop. Therefore typical gate valves are not intended to be used as a regulating valve, unless specifically modified for that purpose. A handwheel must be turned many times 360° to go from fully closed to fully open position, which explains why gate valves are referred to as multi-turn valves, just like globe valves.
The gate can be wedge shaped or parallel and slides between planar seats in the body. The wedge can be solid, flexible or split wedge. The flexible wedge is a good compromise between the strength of a solid wedge and the self-adjusting flexibility of a split wedge. In some cases the solid wedge can be coated with a resilient EPDM or NBR lining for tight shut-off, typically used in (potable) water applications.
 
gate valve - basic componentsThe body can be flat, oval or circular shaped and have flanged, screwed or welded connections. The welded connections are leakage free but are difficult to remove from the pipeline for maintenance or replacement.
 
Gate valves can have a rising or non-rising stem. The first offers a visual indication of the valve position, but needs more free space above the valve. With non-rising stems, the stem is threaded into the wedge. These are typically used for underground installation.
There are different bonnet types depending on the application. Screwed or union-type bonnets are the simplest design, often used for brass gate valves. Bolted bonnet is used for higher pressure and larger valves. A pressure seal bonnet is a special construction where the sealing is actually improved when the internal pressure increases, unlike the other bonnet types where a higher pressure tends to cause more iwc replica watches leakage.

 
The stem of a gate valve must be of a high finish and is typically sealed with graphite (or PTFE) packing material in the stuffing box. Belleville washers are often used to apply a constant compression force on the packing rings, compensating for fluctuations in operating conditions or wear and ensuring a better reliability and reducing fugitive emissions.
 
gate valve - typical1The seat rings are screwed or pressed and welded into the body. They can have hard facing or Stellite overlay for more demanding applications. API 600 defines different materials of seats, stem and wedge for different so called trim numbers.
 
Advantages of gate valves
·straight flow, low pressure drop
·bidirectional (can be used with flow in two directions)
·high capacity (Cv value)
 
Disadvantages of gate valves
·size & weight (compared to ball and butterfly valves)
·not suitable for quick opening/closing
·not suitable for regulating or throttling
 
A simplified version of the gate valve is the knife gate valve, having no stuffing box and being limited to PN16/10 or even lower for larger sizes rolex replica watches uk.
 
 
 
Where can I find gate valve suppliers & manufacturers?
In our buyers’ Guide/Valve directory you will find many manufacturers and distributors of gate valve, both worldwide and locally. List of gate valve suppliers
 
  
 
Gate valve tutorial videos

 
(Courtesy FBV, Inc.)
 
 
International standards related to gate valves
(This list does not pretend to be complete. Only standards where gate valves are mentioned in the title have been listed here. Other - general - standards may be applicable as well)
 
API 6D/ISO 14313 : Specification for Pipeline Valves (Gate, plug, ball and check valves)
API 595 : Cast iron gate valves, flanged ends
API 597 : Steel venture gate valves, flanged and butt weld ends
API 600/ISO 10434 : Bolted bonnet steel gate valves for petroleum and natural gas industries
API 602 : Compact steel gate valves; flanged, threaded, welding and extended body ends
API 603 : Corrosion-resistant, bolted bonnet gate valves – flanged and butt-welding ends
API 604 : Ductile iron gate valves – flanged ends
API 606 : Compact carbon steel gate valves (extended body)
API RP-621 : Reconditioning of metallic gate, globe and swiss replica watches uk check valves
 
BS 1414 : Steel wedge gate valves (flanged and butt weld ends) for the petroleum, petrochemical and allied industries
BS 1952 : Copper alloy gate valves for general purposes
BS 3464 : Cast iron gate valves for general purposes
BS 5150 : Cast iron wedge and double disc gate valves for general purposes
BS 5151 : Cast iron parallel slide gate valves for general purposes
BS 5154 : Copper alloy globe, globe stop, check and gate valves for general purposes
BS 5157 : Steel gate (parallel slide) valves for general purposes
BS 5352 : Cast and forged steel wedge gate, globe, check and plug valves, screwed and socket welding, £DN50, for petroleum, petrochemical and allied industries
 
DIN 3352 : Gate Valves
DIN 3441 Part 6 : U-PVC valves : gate valves with inside screw stem; dimensions
 
EN 1171 : Industrial valves : cast iron gate valves
EN 1984 : Industrial valves : steel gate valves
EN 12288 : Industrial valves : copper alloy gate valves
 
ISO 5996 : Cast iron gate valves
ISO 6002 : Bolted bonnet steel gate valves
ISO 10434/API 600: Bolted bonnet steel gate valves for petroleum and natural gas industries
ISO 16139 : Industrial valves : Gate valves of thermoplastic materials
 
MSS SP42 : Class 150 corrosion resistant gate, globe, angle and check valves with flanged and butt weld ends
MSS SP70 : Cast iron gate valves, flanged and threaded ends
MSS SP80 : Bronze gate, globe, angle and check valves
MSS SP81 : Stainless steel, bonnetless, flanged knife gate valves
 
 
 
 
Do you want to comment or contribute to this page? Please let us know and contact us.
 
© 2013 - Gope Media Group
 
 

Newsletter
Subscribe to our Newsletter
Get the latest news in the valves and sealing world straight in your mailbox.
It's easy and it's free.



What are you looking for?












Home | Copyright | Terms of Use | Privacy Policy | Advertise | Site Map | Contact Us
© 2008 - 2013 Gope Media Group, Herent, Belgium - All rights reserved | Created by Creatief