Helical pressure gauge

The helical elements produce more free-end traveland torque than spiral elements. Other advantages include a higher range of operating pressure with sufficient over range protection. The operating range is affected by coil diameter, wall thickness, the number of coils used, and the material of construction, which is the same as may be used in C-tube elements . Applications of helical elements include direct reading for the following: indicators, recorders, controllers, switches, transmitters, and differential instruments when pressures are applied to both sides of the elements.




Applicationsof helical Pressure Gauge:

Sensing elements for the measurements of medium to high pressures using atmo-spheric reference. For pressure gauges and switches using these elements.

Design Pressure:

Up to 100,000 PSIG (690 MPa)

Design Temperature:

Up to 600 ° F (316 ° C) with stainless steel Bourdon tube; lower with others; ± 1% zero shift per 50 ° F (28 ° C) ambient variation

Materials of Construction:

Phosphor bronze, alloy steel, 316 and 403 stainless steel, beryllium copper, Monel,Ni-Span C

Range:

Minimum span 15 PSI (100 kPa); maximum span 100,000 PSI (690 MPa)

Price:

$50 to $300 for indicators and switches, $500 to $1,200 for direct recorders, and$750 to $1,800 for direct controllers and transmitters. Quartz helix units range for$2,500 for an electronic transmitter to $18,000 for an IEEE and RS-232 program-mable, stable-alone station.

Advantage and disadvantage of helical pressure Gauge

Advantage :-

Disadvantage :-

Very expensive as compared to other types of pressure gauge.