What is the technical specification for a control valve?
Control Valve Technical Specification 9 4.2.3 Seat Leakage Seat leakage classification shall be in accordance with FCI 70-2 or MSS-SP- 61. The leakage class shall be determined by the service application. Soft- seated valves shall not be applied in services with design temperature conditions over 230°C (450°F) or in flashing liquid services.
How is the leakage class of a soft seated valve determined?
The leakage class shall be determined by the service application. Soft- seated valves shall not be applied in services with design temperature conditions over 230°C (450°F) or in flashing liquid services. Leakage problems are commonly related to insufficient seat loading.
What are the requirements for a valve test?
Validation testing/Performance Requirement PR1 PR2 (Pressure/ Temperature cycles) • Force measurement open/close • Dynamic cycling at ambient temperature • Maximum/minimum temperature cycling • Pressure/temperature cycles • Ambient temperature seal test
How is the flow rating of a valve determined?
With it, more parameters can be defined. Rated flow can be determined from the metering curve shown, as long as the supply pressure is set to and maintained at the valve’s flow rating pressure: PS,QR is the supply pressure used for flow rating purposes. For servovalves (ISO 10770-1), the standard test pressure is 7 MPa (1,015 psi).
What should the valve guide clearance be on a sump engine?
Troutman says that for a standard wet sump engine that isn’t spraying oil in the valvesprings, he normally like to see the valve guide clearance to be between 0.0015 and 0.002 of an inch for standard 11/32 inch valvestems. This is for both iron and aluminum heads.
How can I check the valve guide clearance?
If you want to check the valve guide clearance on a cylinder head during a teardown–or if you want to check after your machinist after he’s returned a freshly redone head–insert the clean stem most of the way into the head but leave enough room that you can still hold the valve.
With it, more parameters can be defined. Rated flow can be determined from the metering curve shown, as long as the supply pressure is set to and maintained at the valve’s flow rating pressure: PS,QR is the supply pressure used for flow rating purposes. For servovalves (ISO 10770-1), the standard test pressure is 7 MPa (1,015 psi).
How many times does a valve have to be tested?
(2) The valve must be tested as part of the manufacturing, as follows: (i) With the valve in the fully open position, the shell must be tested with no leakage to a pressure at least 1.5 times the maximum service rating. (ii) After the shell test, the seat must be tested to a pressure not less than 1.5 times the maximum service pressure rating.