This is a stock item. Order by 5pm Monday to Thursday and 4.30pm Friday for same day despatch.
The Altecnic / Caleffi series 309 temperature & pressure relief valve controls and limits the temperature and pressure of the hot water contained in a domestic storage heater and prevents it from being able to reach temperatures of over 100°C, with the formation of steam. On reaching the settings, the valve discharges a sufficient amount of water into the atmosphere so that the temperature and pressure return within the system’s operating limits.
The valve opens the outlet on reaching the settings for:
Temperature: the thermostat compound inside the temperature sensor 1) submerged in the hot water storage heater, expands as the temperature increases. This expansion causes a thrust pin to move and act on the obturator 2) opening the valve. The valve is set to open at temperatures of over 90°C.
Pressure: the obturator, opposed by a set spring, raises on reaching the pressure setting and opens the outlet completely. The pressure setting is chosen according to the maximum permissible pressure in the system.
As the temperature and pressure decrease, the opposite action occurs, with the valve subsequently re-closing within the set tolerances.
Specification
Size: 3/4"
Connections: Male x Ø 22 mm with compression fitting for copper pipe
Materials: DZR
Medium: Water
Set Pressure: 10 Barg
Discharge Rating: 25 kW
Temperature Setting: 90 degC
Probe Length: 99mm
Product Code: 309500CST
Notes: WRAS approved, CE marked