Excess Flow Valves
SENTRY GS Excess Flow Valves
SENTRY GS are designed to close, shutting off the gas flow, when a predefined flow rate is reached. Gas utilities use excess flow valves (EFV) to minimize the risk of damage in the case of a break in the gas line. SENTRY GS have been used successfully and effectively for more than 25 years in underground gas service lines and residential installations throughout the world. In Germany alone, more than 1,000,000 Maxitrol excess flow valves are currently in service.
Maxitrol EFVs are adjusted at the factory, providing a precise and reliable closing flow rate. In the nominal flow range, the EFV remains in a stable, open position. If equipped with a bypass, SENTRY GS reopen after the downstream line has been repaired and re-pressurized.
- Nominal sizes from DN15 to DN50 (d20 to d63)
- Operating pressure ranges from 1,5 to 500 kPa
- Factory-tested both individually and as a complete unit
- No synthetic materials used for components transmitting energy
- Maximum closing flow rate of 1.45 times the nominal flow rate
- Narrow tolerance calibrated by-pass orifice to ensure a quick reopening
- Low pressure drop
- Patented damping system to greatly reduce the number of nuisance shut-offs
SENTRY GS for Residential Installation
Excess flow valves for in-house gas installations are installed downstream of the main gas manual shut-off valve (ECV). SENTRY GS are also available in combination with a thermally activated cut-off device SENTRY GT, that shuts off the gas flow at temperatures between 92 °C and 100 °C.
This SENTRY GS EFV is installed downstream of the regulator and prior to any multilayered pipe. SENTRY GS EFVs with bypass orifice reopen automatically after the downstream line has been repaired and re-pressurized.
Complies with the new AS/NZS5601.1 (Clause 5.2.11) Installation Codes (mandatory March 31, 2023 for Australia)
- Operating pressure range: EU 1.5–10 kPa (AU/NZ 1.25–10 kPa)
- SENTRY GS “Z” model is for horizontal and upward flow direction
- SENTRY GS “D” model is for downward flow direction only
- Threaded connections comply with EN 10226–1 (ISO 7–1) from ½” to 2″ (DN 15–50)
- BS 746 connections available
- Nominal flows from 1.6 m3/h natural gas to 16 m3/h
- Closing factor of type “K” is between 1.3 and 1.45. The trip flow is 30–45 % above nominal flow.
(In Germany only this type of EFV can be used with composite pipe or PEX pipe. It is the type “K” per definition in the standard DIN 30652–1.)
- Maxitrol patented damper function (DN 15 — 25) can avoid a nuisance shut-off in case of flow peaks.
SENTRY GS for Gas Service Lines
Excess flow valves are preferably installed in the branch line off the main gas line and in the gas service line. The SENTRY GS for underground service lines can be special ordered to fit customer-specific installation requirements. We can supply the EFVs in electrofusion couplers and reducers. SENTRY GS are easily traced with a barcode (optional) on the fitting. An ID-Card, showing the product information is delivered with the standard SENTRY GS.
|🇬🇧 SENTRY GS Excess Flow Valves; Residential
Literature; Excess flow valves for residential installations.
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Literature; Excess flow valves for gas service lines.
|🇬🇧 SENTRY GS Excess Flow Valves; Sentry GT Thermal Cutoff Devices
Thermal cut-off devices for legacy installations & excess flow valves for the UK.
|🇦🇺 SENTRY GS Excess Flow Valves; Residential
Literature; Excess flow valves for residential installations in Australia and New Zealand