J
You get valve torques and you get actuator torques. they often come in the form of a maximum torque that can be applied to the stem before damage will occur and also operating torques. so ball valve will often have a MAST (max allowabe stem torque) and also BTO (Break to Open) torque...
All valves have torque figures are standard, where these can not be obtatined then the following can be done:
Carry out breakout tetsing to the valve, this would consist of pressuring valve and recording required torque to operate, run and close the valve and vice versa. As your valve is of...
Washers in teheory are great but if the protective coating becomes damaged you expose the base material which will suffer corrsion, if corrsion occurs then the washer thins in size.When the washer thins the bolt pre-load reduces and therfor the torque decreases until a point when a pressure...
API 6D and API 598 both call for a tight shut off if the valve is soft seated, the leakage rate differs between the specifications when you move to metal seat designs. the preesure you work to will depend on class rating, as mentioned above both the API specs refrence B16:34 for pressures based...
Spray stellite is the easist to apply, if being honest a new valve is required to be purchased with a wear resisatnt coating in place at time of machining. The seat up and machine time required to cnduct this scope of work would be very high
You may have a shaft which is sitting untrue or miss shaped and therefor not allowing for adequate squeeze on your seal resulting in the leak witnessed.
Single piston effect by Single piston effect would indicate to be that a cavity relief ball valve has been requested. this is readliy available and would require the valve to be trunnion mounted i think
Vesselman25
given that an oribit is in theory a single seat ball valve, would a cavity relief ball valve not be sufficient? Given the specification of the orbit i.e. the materials of construction, many ball valves are on the market on the shelf, however, they would require to modified to meet...
Stiaf,
when you mean shock the valve are you referring to applying a differential pressure test? i would have thought that venting the cavity quickly could a can lead to o-ring / lipseal extrusion issues. The cavities on DPE seat x DPE seats should be fitted with a cavity PSV to prevent...
Hi
i have a requirement to supply valves in Alloy 20 GR CN7M. i dont know much about this material but the working temp is 110°C with produced water, iw as looking at the option of 25cr duplex or carbon steel with and overlay. can anyone provide more details about the Alloy 20
thanks
Dean
Serrated finish is oftemn used to provide a seal between to pipe face for pressure 900lbs and below. Generaly you will see them on Raised face end conncetions. The easist way to describe it is if you were to run your nail down the surface it would feel like a very shallow thread form from a...
It will mainly depend on the operator fitted, if it is a standard gearbox the chances are high that the ratio is poor an the operation time is very high with multiple turns of the hand wheel. Gearbox multiplier or ratio boxs can be fitted that will increase speed of operation along with...