Pressure gauge

Syphon

Shay backhead showing the syphon protecting the pressure gauge.

From Chaski.org

Question: I have a pressure gauge designed for air compressors. Can I use this same gauge with steam?

Answer: The gauge will work OK, but you need to be sure to have a loop, aka "syphon", in the tubing going to the gauge, to keep the hot steam from entering the gauge directly. The syphon will fill with condensed water, so steam does does not enter the gauge directly from the boiler.

Support

Clica posted on Chaski.org]:

A State of Michigan deputy boiler inspector told me that you must NOT support the gauge by the syphon pipe. The gauge must have a separate means of support. This is also a requirement on the prototype.

Harold replied:

That's just good sense. If a gauge is mounted by the pipe, vibration will work harden the copper, eventually leading to the pipe breaking.

External Links

• "Pressure Gauge", Chaski.org
• "Steam gauge face", Chaski.org
• "Pressure measurement", Wikipedia
• "Gauge Syphon tubes", Chaski.org
• "Pressure Gauge Syphon", Chaski.org
• "syphon line and seating check balls", Chaski.org