Flat Glass Gauge Valves - Carbon Steel

We offer offset and straight pattern valves that isolate the gage chamber from the liquid contents of the vessel.

Offset valves have an advantage of permitting the inside of the gage glass to be cleaned easily with a minimum of disassembly. By removing the 1/2" vent and drain plug, a straight passage through the gage chamber is opened. A brush can be inserted through the valve vent and drain for glass cleaning.

Both upper and lower valves in each set are equipped with horizontal ball checks. Balls are located on the vessel side of the valve seat.

Valves with ball checks omitted meet ASME boiler requirements, the lower valve is available with an optional vertical rising ball check located in the offset portion of the valve body, and the upper valve has a leaky seat.

Valves shown are offset.

The offset distance from valve stem center to gage center is 3/4".

Model 498 which has an Outside Screw & Yoke bonnet (OS&Y) is not shown.


• Sizes 1/2" NPT up to 1" Flanged
• Offset Pattern, Straight Avail.
• Union Vessel Connections
• Rigid or Union Gauge
• Conforms to AISI / ASTM Specs
• ASME Boiler Code Acceptable
• Auto Ball Check Shutoffs
For Steam/Water Service

4000 psi @ 100F /
   2620 psi @750F

Body: Carbon Steel (316SS is Opt.)
Stem Packing: Grafoil
Trim: Stainless Steel

A Special Note About Corrosion
• Excessive corrosion may result in
   leakage, glass breakage, and
   premature valve failure.
• Be sure all wetted components of the
   gauge are constructed with materials
   compatible with the service medium.
   John C. Ernst Co. does not make    chemical compatibility
• See the "Compass Corrosion Guide"
   or equivalent for material compatibility

For compatible Gauges select Low or Medium Pressure Gauges
Model Vessel
Size NPT
450-04 CSR 1/2" Rigid Integral
450-04 CSU 1/2" Union Integral
450-05 CSR 3/4" Rigid Integral
450-05 CSU 3/4" Union Integral
450-06 CSR 1" Rigid Integral
450-06 CSU 1" Union Integral
460-04 CSR 1/2" Rigid Union
460-04 CSU 1/2" Union Union
460-05 CSR 3/4" Rigid Union
460-05 CSU 3/4" Union Union
460-06 CSR 1" Rigid Union
460-06 CSU 1" Union Union
498-04 CSR 1/2" Rigid OS&Y
498-04 CSU 1/2" Union OS&Y
498-05 CSR 3/4" Rigid OS&Y
498-05 CSU 3/4" Union OS&Y
498-06 CSR 1" Rigid OS&Y
498-06 CSU 1" Union OS&Y

Catalog Page 36
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John C. Ernst Co., Inc.
Sparta, NJTel: 973-940-1600Fax: 973-940-1620
Toll Free: 1-888-463-7678

Email: info@johnernst.com

Mailing Address
21 Gail Court
Sparta, NJ 07871
Physical Address
21 Gail Court
Sparta, NJ 07871