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Home > Temperature & Pressure Pete's Plug > 310 Series P & T Plugs and Accessories

Temperature & Pressure Plugs and Accessories, Sizes: 1/4" TO 1/2",310 Series

Take pressure or temperature readings quickly

These economy plugs will allow you to take pressure or temperature readings - quickly and eliminate the need for leaving costly gauges or temperature indicators on the line.


In general these plugs are a time and money saving device which is well suited for most plant and pipeline systems and is designed to eliminate gauge cocks and thermometer wells. Hot and chilled water systems, heat exchangers, pumps, differential readings, air, gas lines, and numerous other applications are only a few of the areas where these plugs are presently being used.

economy temp and pres plugs

Valve Materials:

Neoprene is a chloroprene based synthetic rubber and is resistant to deterioration from waxes, fats, oils, greases, petroleum products, and most refrigerants.

Nordel is an ethylene-propylene based synthetic rubber and gives excellent service in hot and cold water and in some applications of low steam. Nordel is resistant to detergents, phosphate esters, ketone, alcohols, and glycols. It is not suitable for petroleum products.

Neoprene and nordel are proprietary materials and the information presented herein is believed to be accurate and reliable. We can assume no liability for results obtained or damages incurred through the application of this information. The information is intended as a guide and if in doubt ask!

How to Operate:

These plugs are permanently installed in the line at recommended test points. The cap protects the valve and provides an additional seal. After the cap has been removed, either a test thermometer or a gauge adapter with the proper pressure gauge can be inserted through the two, self-closing valves in the plug. Readings are made, adjustments or test can be accomplished and when the probes are withdrawn, the two valves close. The protective cap is then reinstalled. Tests should be made as quickly as possible since the valve reseal time is dependent upon time of insertion, time, and pressure. Slower valve reseal time can be expected at lower temperature and lower pressures.


  • Available in 1/4" and 1/2" NPT sizes
  • Available in long length
  • Brass body material for non-corrosive service
  • Pressure limits to 1000 psi depending on application
  • Neoprene core (red cap) for temperature range of 0-200°F, for use with natural gas and petroleum products
  • Nordel core (blue cap) for temperature range of 0-275°F, for use with hot and chilled water systems
  • Valve core is self-sealing with pressure cup for superior sealing protection
  • Tested by an independent lab indicates no leaks at high or low pressure

310 Series Pressure and Temperature Plugs
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Cap retaining straps are standard on all brass plugs.

Pressure Gauge Probe Adapters

The pressure gauge adapter has a probe constructed of 304 stainless steel. The probe is 1/8" in diameter and extends 2" (1 1/2" exposed probe) on the 312-500 adapter and 3 1/2" (3" exposed probe) on the 312-500-XL adapter. The 1/8" diameter probe operates in either the 1/4" or 1/2" Plug. The 312-500-XL Pressure Gauge Probe Adapter will operate in any of the Plugs.

Pressure Gauge Probe Adapters
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Temperature Gauges

The analog thermometers are constructed of stainless steel, has a 1 3/4" dial and accuracy within 1/2% over the entire scale. Recalibrations is by turning the hex nut on the back of the dial case with stem immersed in a known temperature bath. Digital thermometers have the same specifications as above but can not be recalibrated in the field.

Pressure Gauges

The 3 1/2" pressure gauge has an ASME B accuracy of 3/2/3% (2% in middle of scale). It has an adjustable red altitude pointer with a psi and feet of water scale.

Bi-Metal Pocket Testing Thermometers, 5” Stem, 0.156” (4mm)
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Compound Pressure Gauges
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Pressure and Temperature Test Kits
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