Boiler Level Control Parts
Primary & Auxiliary / Secondary Low Water Cutoffs
Primary Low Water Cutoffs
A boiler's primary low water cutoff is a mechanical device with multiple functions:
- Senses water level in the boiler through a mechanical float and shuts the boiler down if water level decreases
- Primary low water cutoffs are typically automatically reset, meaning the boiler can automatically restart once water level is restored
- Provides a rigid body to connect a gauge glass and try cocks
- Regulates boiler water level via on-off pump control or by sending an open/close signal to a modulating feedwater valve
Gauge Glasses & Try Cocks
Gauge glasses are used to provide visual indication of water level in a boiler. Typically the gauge glass is mounted directly to the boiler's primary low water cutoff via 1/2" NPT connections machined into the LWCO body. A complete gauge glass assembly typically consists of:
- Gauge glass fixture consisting of upper and lower isolation valves
- Metal rods to protect the glass from being hit
- Drain valve available on some models
- Tubular high temperature glass
- Gauge glass washers to create a seal between the glass and the fixture
