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Gauge Guards – also known as Diaphragm Seals or Instrument Isolators Series GGS





  • Choice of Geon® PVC, Corzan® CPVC, Natural Polypropylene, Glass-Filled Polypropylene, Kynar® ggs replacing ggm
  • Available with or without gauge (dual in PSI and bar). When ordered with gauge, it includes a premium 2 1/2″ stainless steel case. Guard with acrylic shield includes 2″ black steel case gauge with brass connection. Both types are offered in pressure or vacuum.
  • NEW Design uses stainless steel hex insert (NON-WETTED) to prevent overtightening.
  • Low cost protection of gauges and other pressure instruments.
  • Available in a variety of thermoplastics for specific chemical compatibility and temperature ranges.
  • Increase product reliability and reduce system downtime caused by failure of instruments not isolated by seals.
  • Compact size makes these isolators ideal for limited space installations.
  • ±3% accuracy. Will handle most applications.
  • Use with gauges, transducers, and pressure switches.
  • Simple to fill and install.
  • For use with highly aggressive or ultra-pure liquids.
  • Diaphragm safety – If the gauge or instrument fractures while the system is pressurized, the diaphragm will automatically seal against leakage to the atmosphere.
  • Standard PTFE diaphragm (except for vacuum and 0-15 PSI; 0-1 bar) for maximum corrosion resistance.
  • Eliminates need for costly exotic metal gauges for corrosive processes.
  • Optional transparent shield for external corrosion protection; available with 2″ black steel gauge only. 



Information for Legacy GGM Users

Please note that Series GGS has superseded the original Series GGM, which was the standard Plast-O-Matic Gauge Guard for over 30 years. Series GGS provides the same pressure ratings, reliability and performance as Series GGM, but has a larger volume upper housing featuring a non-breakable, solid hex stainless steel (non-wetted) gauge fitting.


Connections & Dimensional Data:

Gauge Port: 1/4 NPT standard 1/2 NPT or BSP available (specify) System Port: 1/2 NPT or BSP Standard Gauge: 2 1/2″ Stainless Steel; Shielded models use 2″ gauge.


                                                                                                                  *Note as illustrations show, revised design uses self-tapping fasteners to hold housing together


For 1/2″ GAUGE CONNECTION add the letter “X” after the product prefix. For example: GGTSX1-PV

For CENTER BACK MOUNTED GAUGE add “-C” as a suffix. For example: GGTS060-PV-C

For OPTIONAL GAUGE FILL PORT add “-FP” as a final suffix. For example: GGTS060-PV-C-FP

Standard diaphragm is PTFE unless specified, or for vacuum or 0-15 PSI gauge applications. Optional FKM is Vinylidene Flouride – Hexafluoropropylene (Fluorocarbon). Viton®, for example, is a specific brand of FKM rubber.

For FKM instead of PTFE change GGTS to GGVS in the product prefix. For example: GGVS200-PV

For EPDM instead of FKM change GGVS to GGEPS in the product prefix. For example: GGEPS015-PV

Gauge Guards Homepage


CAD Files

GGS in STEP format

Additional Info: