Clark Reliance Water Gage Valves — BG, SG600, SG700, SG800 Series — Northeast Controls Inc.
Northeast Controls Inc.

Clark Reliance

Bronze & Steel Water Gage Valve Sets

BG Series · SG800 Series · SG600 & SG700 Series · 450 PSI to 3000 PSI

Clark-Reliance water gage valve sets provide reliable isolation of boiler water level gages from vessel pressure. Available in 12 bronze models for service to 450 PSI and 16 forged steel models for service to 3000 PSI, these valves are designed and manufactured to meet the requirements of the ASME Boiler and Pressure Vessel Code.

All bronze BG Series valves feature an 18-position gage lever, integral seats, and quadruple stem threads for full open/closed operation with only one-quarter turn. Forged steel SG Series valves feature ASTM SA-105 bodies, Type 303 stainless steel stems, and Grafoil packing cartridges for leak-free operation at elevated pressures and temperatures.

Series Overview

BG Series

To 450 PSI (31 Bar)

Material: BronzeOperation: Lever OperatedTemperature: Steam service

Compliant bronze body and packing nuts per ASME BPV Code. 18-position gage lever standard. Screwed NPT and 300# RF flanged connections.

SG800 Series

To 1500 PSI (100 Bar)

Material: Forged SteelOperation: Lever OperatedTemperature: 600°F service

Outside screw and yoke design. ASTM SA-105 forged steel body. 420F stainless steel replaceable seat. Grafoil packing cartridge. 18-position gage lever.

SG600 & SG700

To 3000 PSI (200 Bar)

Material: Forged SteelOperation: Chain Wheel OperatedTemperature: 700°F service

Exclusively chain wheel operated. ASTM SA-105 forged steel body. Grafoil packing cartridge. Single-pitch stem thread for easy chain wheel operation.

BG Series — Bronze Water Gage Valve Sets

Lever operated · To 450 PSI (31 Bar) · Compliant bronze body per ASME BPV Code

Each complete valve set includes upper valve, lower valve, and two 5-foot lengths of chain. Lower valves include a 3/8" pipe tap for blowdown. Note: Clark-Reliance does not recommend tubular glass above 250 WSP.

ModelDesign Pressure PSI (Bar)Vessel ConnectionWt. (lbs.)
BG251S250 (17)¾" Male NPT w/ Ball Checks8
BG252S450 (31)¾" Male NPT w/ Ball Checks8
BG402S250 (17)½" Male NPT8
BG403S250 (17)¾" Male NPT8
BG404S450 (31)¾" Male NPT8
BG502RAS250 (17)¾" 300# RF Flange13
BG503RAS450 (31)¾" 300# RF Flange13
TG602RS250 (17)½" Male NPT13
TG603RS250 (17)¾" Male NPT20
TG604RS450 (31)¾" Male NPT20
TG605RS250 (17)¾" 300# RF Flange28
TG606RS450 (31)¾" 300# RF Flange28

SG Series — Forged Steel Water Gage Valve Sets

SG800: lever operated to 1500 PSI at 600°F · SG600 & SG700: chain wheel operated to 3000 PSI at 700°F

All models: ASTM SA-105 forged steel body · Type 303 SS stem · Grafoil packing cartridge · ½" SW drain connection (SG778S uses ½" NPT/SW). To specify for welding to water columns, add "C" to model number (e.g., SG777S → SG777CS).

ModelDesign Pressure PSI (Bar)Vessel ConnectionBall ChecksGage ConnectionWt. (lbs.)
SG677S3000 (206)¾" Female SWOptional½" 2500# RTJ27
SG777S2500 (172)1½" Female SWOptional½" 2500# RTJ20
SG777CS2500 (172)¾" Male NPTOptional½" 2500# RTJ18
SG777CMSW2500 (172)¾" Male SWOptional½" 2500# RTJ18
SG778S1500 (103)1½" Female SWOptional¾" OD Nipple18
SG854S1500 (103)¾" Male NPTNo¾" OD Nipple15
SG854F-300605 (42)¾" Male NPTNo¾" 300# RF20
SG854F-6001135 (78)¾" Male NPTNo¾" 600# RF22
SG854F-9001500 (103)¾" Male NPTNo¾" 900# RF24
SG855S1500 (103)¾" Male NPTYes¾" OD Nipple16
SG860S1500 (103)¾" 900# RF FlangeNo¾" OD Nipple24
SG861S1500 (103)¾" 900# RF FlangeLower only¾" OD Nipple24
SG861US1500 (103)¾" 900# RF FlangeYes¾" OD Nipple24
SG885S1135 (78)¾" 600# RF FlangeLower only¾" OD Nipple24
SG885US1135 (78)¾" 600# RF FlangeYes¾" OD Nipple24
SG886S1500 (103)¾" Male NPTLower only¾" OD Nipple15

Accessories & Options

Ball Check Valves — Model SG77BC

Automatic ball check valves protect against blowout damage in the event of glass breakage or gasket failure. Comply with ASME Boiler Code Section I, Paragraph A-18. Factory installed on applicable SG Series models.

SG77BCU — Upper Ball Check ValveSG77BCL — Lower Ball Check ValveSG77BC — Ball Check Valve Set

Live-Loading Retrofit Kit — RK-34

Improves performance, extends service life, and produces more leak-free operation. Resists vibration damage and handles pressure changes and wear. Fits all SG700 and SG800 Series models. Available as a specified option on new valves.

Kit includes: 2 cap screws, 4 flat washers, 1 graphite packing cartridge, 8 spring washersTo order on new valves: Add "P" to model number (e.g., SG854S → SG854P)

18-Position Gage Lever

Patented Clark-Reliance gage lever provides positive, non-slip locking in 18 positions. Standard on all BG Series bronze valves and SG800 Series forged steel valves. Readily adjusted to the desired angle regardless of valve stem orientation when the valve is closed.

One-Piece 420F SS Valve Seat

Machined from 420F stainless steel for precise fit and flow surfaces. Provides faster renewing, improved performance, and longer service life compared to traditional multi-piece seats. Standard in SG700 and SG800 Series.

Design Features

→Forged steel body to ASTM SA-105 specification (SG Series)
→Compliant bronze body per ASME BPV Code (BG Series)
→Type 303 stainless steel stem (SG Series)
→Quadruple stem threads — full open/close in ¼ turn (BG & SG800)
→Grafoil packing cartridge for leak-free operation (SG Series)
→Stem bushing positioned outside body, away from heat and corrosives
→18-position gage lever standard on BG and SG800 Series
→One-piece 420F SS replaceable seat (SG700 & SG800 Series)
→Outside screw and yoke design (SG800 Series)
→Chains and handles indicating open/closed positions (BG Series)
→Ball check valves available per ASME Boiler Code Section I
→Live-loading retrofit kit available for SG700 & SG800 Series

Request Pricing — Clark Reliance Gage Valves

1+201-419-6111 · [email protected]

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