stop globe/check, difference?

[cheaterbar]

I'm back with another question after receiving very good replies previously.

I don't see a difference with Stop Globe and Stope Check valves, design wise. Is there a difference?

Thanks for your help.

 

[insult2injury]

Their constructions are very similar. When the stem is retracted in a stop check, the shaft is not connected to plug; therefore, leaving the floating plug to perform as a check valve. With the globe, however, the plug is pulled off the seat when the stem is retracted.

I2I

 

[gerhardl]

.. or another way to look at it, is to start at a globe check valve. The globe in a globe check valve is guided and usually also spring loaded to open freely at a certain small overpressure in flow direction to overcome weight of globe and spring force in addition to the (return) after pressure.

To make a stop globe valve from this startpoint you have to add the usually threaded spindle to force the valve open if closed and force the valve open if closed.

The difference from a normal stop globe valve is the ability of the globe to freely move open and close as a check valve if not locked by the spindle in closed position.

The attachment and griping between stem and globe will have to differ from a normal stop valve, in addition to (usually) additional spring and guiding arrangment for the globe.

Suppliers that both have globe valves and 'closeable / lockable globe check valves and globe check valves, will try to use as many equal parts as possible for the three variations, where housing is the most obvios common factor.

Top, spindle details and details for globe will vary. Seating and some sealings may be equal.