Double function safety valve temperature and pressure

Technical specifications

Materials:

• Body: Brass UNI EN 12165 ADZ CW602N
• Internal Stem: Nylon 30% fiber glass
• Obtur. and diaphr. EPDM
• Spring: Steel UNI EN 10270-1 SH
• Control Knob: PA6GF

Nominal pressure:

• PN 10
• 1/2″ e 3/4″ Ø15; 10kW
• 3/4” Ø22; 25kW

Medium:

• water

PED Category:

• IV

Settings:

• temperature 90°C
• pressure 3-4-6-7-8 bar

Connections:

• 1/2”M x Ø15 mm with compression fitting for copper pipe
• 3/4”M x Ø15 mm with compression fitting for copper pipe
• 3/4”M x Ø15 mm with compression fitting for copper pipe

Function

The TP double function relief valve controls and limits the temperature and pressure of 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. This particular series of valves is certified as conforming to the performance requirements of the European standard EN 1490 (for settings of 4-7-10 bar).

Operating principle

The valve opens the outlet on reaching the settings for:

• Temperature: the thermostat compound inside the temperature sensor 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 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 reclosing within the set tolerances.

Certification

CE MARK TP: double function relief valves comply with the essential safety requirements of Directive 2014/68/UE/P.E.D. concerning pressure equipment (also called PED). They are therefore classified as category IV and are equipped with the CE mark.

Product certification in accordance with European standard EN 1490

European Standard EN 1490: 2000, entitled “Building valves – Combined temperature and pressure relief valves – Tests and requirements”, describes the constructional and performance specifications that TP relief valves must have.