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Cast Steel Bolted Bonnet API 600 Valves Overview
 

gate valveS


gate valves are the most commonly used shutoff valve in the industry today. They are used where minimum pressure drop and bi-directional on-off service is required. Gate valves are not designed for throttling service. Prolonged use in the partially open position will generally damage seating surfaces. Gate valves are available with a number of wedge configurations (solid, flexible and split) to best meet the specific service conditions. Gate valves normally are handwheel operated, but are also available with gearing, electric motor actuators, or cylinder (pneumatic or hydraulic) actuators for remote operation. See Actuators and Accessories section for more detail.

 

globe valveS


globe valves are used where throttling or both throttling and shutoff are required. They can also be used for on-off service, but because of high pressure drop, this is generally confined to applications where the valve is normally closed and pressure drop is not important when the valve is open. Normally globe valves are installed with flow under the disc, but under certain conditions flow over the disc may have advantages. Standard globe valves, because they are designed for both throttling and shutoff, should not be used for prolonged throttling at less than 10% open. Internal damage can occur. Using a smaller valve or V-port trim to increase the percent open will often solve this problem. V-port trim has a more linear throttling curve than plug or ball discs, but none of these trims are recommended for continuous severe throttling which may require using a control valve. Pacific Valves will be glad to advise you on your application. Globe valves are available with a complete range of manual or remote actuators. See Actuators and Accessories section for more detail.

 

 

Selection

TYPE AND SIZE – Select the best type of valve for the intended service (gate, check, etc.). Gate and globe valves are available with a selection of wedge or disc configurations for different services. Valves may be sized to match existing lines, but swing check and stop-check valves should also be sized according to flow conditions for maximum service life.

  

RATINGS – Valves must only be used in operating conditions within the appropriate ANSI pressure-temperature ratings for valve class rating and body/bonnet material (see Technical Data section).

  

MATERIAL AND SERVICE – Cast steel bolted bonnet valves are available in a variety of body/bonnet materials and trims.

 

From: NVF valve knowledge

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