100 Series High Capacity Sealed Heating System Pressure Relief Valve

Disclaimer: All images are for illustrative purposes only.

Discharges water off the system at a set pressure in the event of system over pressurisation (high for larger capacity systems)

Reliance Valves 100 Series Pressure Relief Valves are made from hot pressed brass and are predominantly used to protect closed-circuit wet heating systems from overpressure. The outlet is one size larger than the inlet to ensure high discharge flow rates.

It has a separate seal seating from the diaphragm to give improved scaling resistance and a cover which is made from OT58 brass. Available in a variety of sizes to suit most installations, it also has a pressure range from 2.5 - 5.0 bar, with the response pressure indicated on the twist cap. The valve size is determined by the heat output of the boiler as shown in the maximum heating capacity table.

Features and benefits

  • High flow design for larger capacity systems
  • Outlet is one size larger than the inlet for high capacity discharge
  • Provides protection against over pressurisation in wet heating systems
  • Diaphragm design gives improved resistance against scale
  • Cartridge design gives ease of service and replacement without the need to reset the response pressure
  • Set pressure range from 2.5 - 5.0 bar to suit any system requirement
  • High lift design for increased discharge capacity
  • Suitable for heating applications only
SKUDescriptionModelBSP Inlet Size ″BSP Outlet Size ″
PREL100001100 Series 1⁄2″ FBSP × 3⁄4″ FBSP 3 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar1⁄23⁄4
PREL100003100 Series 1⁄2″ FBSP × 3⁄4″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar1⁄23⁄4
PREL100004100 Series 1⁄2″ FBSP × 3⁄4″ FBSP 5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar1⁄23⁄4
PREL100008100 Series 1⁄2″ FBSP × 3⁄4″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar1⁄23⁄4
PREL100013100 Series 3⁄4″ FBSP × 1″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar3⁄41
PREL100014100 Series 3⁄4″ FBSP × 1″ FBSP 3 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar3⁄41
PREL100016100 Series 3⁄4″ FBSP × 1″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar3⁄41
PREL100022100 Series 1″ FBSP × 1 1⁄4″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar11 1⁄4
PREL100023100 Series 1″ FBSP × 1 1⁄4″ FBSP 3 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar11 1⁄4
PREL100025100 Series 1″ FBSP × 1 1⁄4″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar11 1⁄4
PREL100027100 Series 1″ FBSP × 1 1⁄4″ FBSP 5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar11 1⁄4
PREL100028100 Series 3⁄4″ FBSP × 1″ FBSP 5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar3⁄41
PREL100032100 Series 3⁄4″ FBSP × 1″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar1 1⁄41 1⁄4
PREL100033100 Series 1 1⁄4″ FBSP × 1 1⁄4″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar1 1⁄41 1⁄4
PREL100034100 Series 1 1⁄4″ FBSP × 1 1⁄4″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar1 1⁄41 1⁄4
PREL100036100 Series 1 1⁄4″ FBSP × 1 1⁄4″ FBSP 5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar1 1⁄41 1⁄4
PREL100041100 Series 1 1⁄2″ FBSP × 2″ FBSP 3 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar1 1⁄22
PREL100042100 Series 1 1⁄2″ FBSP × 2″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar1 1⁄22
PREL100044100 Series 1 1⁄2″ FBSP × 2″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar1 1⁄22
PREL100046100 Series 1 1⁄2″ FBSP × 2″ FBSP 5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar1 1⁄22
PREL100049100 Series 2″ FBSP × 2 1⁄2″ FBSP 3 Bar Pressure Relief ValveFemale Connections Pre-set at 3 Bar22 1⁄2
PREL100050100 Series 2″ FBSP × 2 1⁄2″ FBSP 4 Bar Pressure Relief ValveFemale Connections Pre-set at 4 Bar22 1⁄2
PREL100052100 Series 2″ FBSP × 2 1⁄2″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 2.5 Bar22 1⁄2
PREL100055100 Series 2″ FBSP × 2 1⁄2″ FBSP 2.5 Bar Pressure Relief ValveFemale Connections Pre-set at 5 Bar22 1⁄2