Call Us: (973) 256-3000 Plast-O-Matic Valves, Inc.
1384 Pompton Avenue
Cedar Grove, NJ 07009 USA

Gauge Guards – also known as Diaphragm Seals or Instrument Isolators

Back to Summary new ggs replacing ggm


  • Choice of Geon® PVC, Corzan® CPVC, Natural Polypropylene, Glass-Filled Polypropylene, Kynar® PVDF.
  • Available with or without gauge (dual in PSI and bar). When ordered with gauge, you have choice of a premium 2 1/2" stainless steel case, or an economical 2" black steel case 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.
new ggs replacing ggm

Comparison of GGS & GGSE

Photo above right is standard Gauge Guard shown with 2˝" Stainless Steel Gauge. Below it at right is Series GGSE, which features the 2" Black Steel Gauge. The 2˝" Stainless features more robust construction, is easier to see, and has a significantly greater resistance to atmospheric corrosion and humidity. The 2" Black Steel Gauge provides a lower cost option with virtually identical performance of the internal instrument. Construction of the Guard portion is the same regardless of the gauge you choose.

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Please note that Series GGS has superseded the original Series GGM, which was the standard Plast-O-Matic Gauge Guard for over 30 years.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.

     Film Click here for a brief video demonstrating how a gauge guard works.

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 GGSE BLACK STEEL GAUGE add the letter "E" prior to the hyphen in the part number. For example, GGTS060E-PV.

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

CAD Files

GGS in .dwg format

Helpful Links:

• For a complete Catalog in PDF format for Series GGS, Please click here.

• For a sample spec that you can cut and paste, please click here

• For Installation Instructions please click here.

• For the Main Gauge Guard Page with links to other types of Gauge Guards, please click here.

Plast-O-Matic Valves, Inc. 1384 Pompton Avenue Cedar Grove,
NJ 07009 USA Phone: (973) 256-3000 Fax: (973) 256-4745
California Warehouse 4054 Brewster Way Riverside, CA 92501
Email: Legacy home page: please click here