Gate Valve Specifications

These typical specifications are recommended for gate valves in the following services 100-pound air, 50-pound caustic, 15-pound condensate, 50-pound fuel, 150-pound hydrocarbon, and 40-pound exhaust. The ratings are 230 psi at 100°F, and 150 psi at 500°F, and 100 psi at 750°F (maximum). 

For 1-1/2-inch and smaller, use 600-pound SWP forged, carbon steel, screwed, inside-screw stem, union bonnet, 11 to 13% chrome stainless steel trim. For air and condensate service use 150-pound SWP brass, screwed, rising stem, inside screw. 

For 2-inch and larger gate valves, use 150-pound ANSI standard cast, carbon steel, flanged, OS Y, 11-13% chrome stainless steel trim, 1/16-inch raised face. For condensate service use 125-pound ANSI standard cast iron, flanged OS Y brass trim, and stem. 

In steam services at 275 psig and 410° F, and hydrocarbon service at 250 psig and 750 to 800°F (maximum) with the following rating  

For 1-1/2-inch and smaller, use 600-pound SWP forged, carbon-steel screwed, inside-screw stem. 

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A pipeline consisting of 1500 ft of 6 in. sch 40 pipe containing 25 90° elbows and four open gate valves carries oil with a viscosity of 35 cP and a specific gravity of 0.85 at a velocity of 7.5 ft/s from a storage tank to a plant site. The storage... 

You must determine the specifications for a pump to transport water at 60°C from one tank to another at a rate of 200 gpm. The pressure in the upstream tank is 1 atm, and the water level in this tank is 2 ft above the level of the pump. The pressure in the downstream tank is 10 psig, and the water level in this tank is 32 ft above the pump. The pipeline contains 250 ft of 2 in. sch 40 pipe, with 10 standard 90° flanged elbows and six gate valves. 

A centrifugal pump and its spare handle 1000 gpm of an oil at 500°F. Its specific gravity is 0.81 and its viscosity is 3.0 cP. The length of the line is 600 ft and its equivalent length with valves and other fittings is 900 ft. There are 12 gate valves, two check valves, and one control valve. 

Replacement of gate valves with ball valves (within the plant valve specifications or within regular usage for that service). (Depending on the level of maturity of your organization, and your written program, this valve substitution and the two examples that follow could require an MOC for this type of situation.)... 

These specifications apply to gate valves used in the following services ... 

Gate valves are not suitable for throttling the flow volume unless specifically authorized for this application by the manufacturer. They generally are not suitable because the flow of fluid through a partially open gate can cause extensive damage to the valve. 

There is a capability to isolate each primary loop from the reactor using two gate valves on the suction and pressure pipelines of the circuit. On the pressure pipeline of each loop downstream of the PSP a flap-type check valve is provided eliminating coolant backflow in the event of a PSP trip in one loop when the other PSPs are operative. The secondary sodium circuits comprise EHX heat transfer tubes, pipelines, secondary sodium pumps and steam generators. Due to utilization of the reactor energy for fresh water production the steam-water system has some specific features. Steam from the SG is supplied to turbines of two types a condensing turbine (K-100-45) and a back-pressure turbine (K-50-45). Exhaust steam flows from the back-pressure turbine and from intermediate bleeds of K-100-45 turbine are supplied to the water desalination facilities. At a heat output of 750 MW the reactor produces ... 

Many diverse devices have been developed for feeding pipelines. Some are specifically appropriate to a single type of system, such as suction nozzles for vacuum systems. Others, such as rotary valves, screws and gate valves, can be used for vacuum and positive pressure systems. The approximate operating pressure ranges for various pipeline feeding devices are illustrated in Figure 4.13. 

For SIL 2 applications the preferred method to achieve separation is to install a separate shutdown valve specifically for shut-off or venting duties. This duty is often met by a ball or gate valve. 

API Specification 6D Specification for Pipeline Valves (Gate, Plug, Ball,... 

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