Pressure gauges, pressure vessel assemblies, and methods of displaying pressure within pressure vessel assemblies

A method of displaying pressure within a pressure vessel, comprising:

• at a pressure gauge having a housing with an inlet conduit extending into an interior of the housing, a helical tube formed from a tube material with a closed end and an open end, the open end of the helical tube connected to the inlet conduit, and a compensation member fixed to the helical tube between the open end and the closed end of the helical tube, the compensation member formed from a material having a coefficient of thermal expansion differing from that of a material forming the helical tube,
• changing temperature of a compressed fluid in thermal communication with the helical tube;
• expanding or contracting one of the helical tube and the compensation member at a first rate corresponding to the temperature change;
• expanding or contracting the other of the helical tube and the compensation member at a second rate corresponding to the temperature change;
• and
• limiting movement of the closed end of the helical with expansion or contraction of the compensation member.

A method of making a pressure gauge, comprising:

• defining a housing having an inlet;
• arranging a helical tube within the housing with a closed end and an open end, the open end of the helical tube in fluid communication with the inlet;
• and
• arranging a compensation member arranged between the between the open end and the closed end of the helical tube, the compensation member fixed to the helical tube,
• wherein the compensation member and the helical tube are formed from materials having different coefficients of thermal expansion to limit movement of the closed end of the helical tube due to temperature change of a compressed fluid in fluid communication with the helical tube.