Noise is generated by mass flow rate and velocity. Certain valves have greater acoustical efficiency (the ability to turn energy into noise) than others.

The valves, ranging would be gate or globe valves, sizes of 8-12" for steam condensate service, sub-atmospheric pressure, ~80 deg. C/ 176 deg. F.

The largest and most potentially dangerous pieces of "blue ice" have been associated with "donut" valves".

I can't seem to find how accurately the Class 4 torques tools for manual valves can be controlled.

The small bypass equalization line is a product of an industry problem with gate valves for thermal binding and presure locking.

Respect to valve that are used in offshore oil and gas industry. A perticular manufacturer supply us valves complying all the testing and specification requirement.

Do seat ring welding rods need to be pre-heated? I've been told that they do not.

If I have understood this correctly, in reverse acting gate valves, you pull the plug up to close the valve. Gate down = open valve.