API RP 615:2010 pdf download
API RP 615:2010 pdf download.Valve Selection Guide.
3.18
pressure seal bonnet
The pressure seal bonnet design is one that features a special compact body-bonnet joint rather than a flange. This body-bonnet joint is pressure-assisted so that with increasing pressure the jo4nt seals more tightly.
solidifying service
Solidifying servce is a general term used to identify fluids that change from liquid to solid unless maintained at certain conditions of temperature, pressure, and flow. It is a term generally associated with fluids such as liquid sulfur and heavy fuel oil in which valves often require heat tracing (e.g. steam-jacketed design) to maintain temperature and valve operability.
3.20
slurry service
Slurry service is a general term used to define liquids with substantial solids in suspension. Often the solid is the product and the fluid is pnmanly the means of transportation. e.g. coal slurries and catalyst services.
3.21
stress cracking
Material failure resulting from exposure to aggressive environments, such as sour or wet H2S exposure, chlorides. hydrogen, and amines. for example.
3.22
sour (wet H2S) service
Wet H2S service is defined as having greater than 50 wppm of H2S in a water phase (determined by using the total amount of sulfide in the water phase) or 0.05 psia H2S partial pressure In the gas phase with liquid water present.
3.23
utility service
Generally considered to indude air, water, nitrogen, and steam not exceeding Class 150.
3.24
viscous service
Viscous service is a term that generally identifies a wide range of fluids with pronounced thickness and adhesive properties. Fluids include high viscosity os (lube and heavy fuel oil) and non-Newtonian fluids such as waxy crude. gels and pastes
4 Considerations for Valve Selection
4.1 Valve Functions
Consideration of valve function:
— stop flow (on-off or isolation valves referred to as block valves),
— prevent flow reversal (check valves including stop-check valves),
— regulate flow (control flow rate by throttling flow),
— prevent overpressure in piping system (pressure relief valves—not in scope of this RP).
5.1.2.4 Metal Seated Ball Valves
Metal seated ball valves, often with a hardfacing on the seating surfaces, have been widely used in high temperaturepressure service as well as applications exhibiting erosive/abrasive characteristics. In the case of manual operation a gear operator is usually needed.
5.1.3 Plug Valves
5.1.3.1 General
Plug valves are designed for on-off service using a truncated cone-sealing element that is typically supported either by a thin grease film (lubricated ph.ig) or by a polymer sleeve (sleeved plug). Some plug valve designs are metal seated to provide for higher temperature service. Plug valves are useful for tight shutoff applications and for highly corrosiv&ecosive services because of its large sealwig area. Common plug valve types are covered in API 599, but there are other plug-type designs used for special applications. Plug valves are not recommended for throttling service.
5.1.3.2 API 599 Plug Valves
Sizes covered in API 599 are NPS 1/2 through 24 for flanged and butt-welding ends and NPS 1/2 through 2 for threaded and socket-welding ends. This standard covers valves that have pressure-temperature ratings in accordance with ASME B16.34 Standard Class for steel and nickel-alloy body and cover materials, and ASME Bi 6.42 for ductile iron. Lubricated plug valves and designs with nonmetallic components such as: seals, sleeves, liners, diaphragms, seats, and sealants may limit the applications of valves to more restricted pressures and temperatures This pressure-temperature limit is to be marked on the valve nameplate. API 599 requires a temperature capability for lubricants and stem seals or packing to have a minimum temperature range of —29 “C (—20 “F) through 107 “C.
