When utilizing pressure gauges in applications with elevated temperatures, it’s important to know the recommended configurations to avoid gauge failure, protect the instrument, and maximize performance and accuracy.

140 °F is the maximum recommended ambient media temperature for pressure gauges with brass wetted parts, and 212 °F for gauges with stainless steel wetted parts. For applications in which media reaches temperatures above 212 °F, there are several accessories designed to prevent damage to the gauge and maintain maximum performance and accuracy.

The guidelines below are intended to be general recommendations. Many conditions may affect the amount of temperature reduction; including ambient temperature, media type, and process configuration.

Up to 140 °F:     The majority of pressure gauges will provide peak performance in this range.

Up to 212 °F:     A gauge with stainless steel wetted parts is required. Do NOT use a gauge with brass wetted parts.

Up to 287 °F:     Accessories must be used to maintain gauge integrity and accuracy. 
    

Options include:

Pigtail Steam Syphon
For use with a stainless steel wetted parts gauge. Should be used in steam applications and systems that contain superheated vapor. The pigtail buffers the instrument from the damaging effects of high temperature steam by holding system fluid in the coil to provide a steam trap for the fluid to condensate and dissipate the heat. Reduces temperature by 75° F/ft. on average. Multiple configurations are available.

Armored Capillary Tube
For use with a stainless steel wetted parts gauge. The capillary line provides a connection between the pressure instrument and the diaphragm seal.
It protects the pressure instrument from high or low process temperatures and provides distant or remote reading.

The capillary should be selected as short as possible, as changes in ambient temperature conditions may considerably affect the accuracy and response time of the pressure instrument. 

Average temperature reduction is 75 °F/ft. Two feet of capillary tube can increase the media 
temperature range to 362 °F. The standard length is five feet, provided with thread connections.

The pressure gauge must be separated from the process with a mounting bracket or flange, and the extra capillary length can be rolled
up if necessary. Recommended for use with clean media or gases.

Long Pipe
1/2″ in diameter or greater in either steel or stainless steel construction with a stainless steel wetted parts gauge. Average temperature reduction is 75 °F/ft.
Pipes can be cut and threaded for custom applications.

Cooling Element
For use with a stainless steel wetted parts gauge. Intended to protect the pressure instrument from high or low process temperature. Air flow across heat exchanging fins reduces or increases the temperature of the system fill fluid to protect the pressure measuring instrument. 

The cooling element is recommended for process temperatures above 212°F. It is direct mounted between the pressure instrument and the diaphragm seal.  Silicone fill is recommended. Effective temperature reductions of 200°F depending upon ambient conditions.  All Stainless Steel construction back welded to Stainless Steel upper housing or flange.

Average temperature reduction is 75 °F/4″ element. Use with other accessories for additional temperature decrease (long pipe, syphon, diaphragm seal).

Cooling Tower
For use with a stainless steel wetted parts gauge. Approved usage up to temperatures of 312 °F. 
Average temperature reduction is 100 °F/8″ cooling tower. Recommended for use with clean media 
or gases.

Up to 300 °F    A high temperature system fill is required, such as silicone D.C 550, and a diaphragm seal is recommended on a Stainless Steel wetted parts gauge.