HERZ Service Ball Valve 1" with Drain, Sealable PN10, 1 2205 03

HERZ 1 2205 03 is a service ball valve for connecting diaphragm expansion vessels in heating, cooling and solar-energy systems. Its design allows the expansion vessel to be safely isolated for inspection, servicing or replacement without draining the entire system.

The nominal size is DN25 and both sides have Rp 1" female threads. Current HERZ manufacturer documentation specifies a maximum operating pressure of PN10 for this model.

The valve is equipped with a separate drain valve, allowing the heating medium between the shut-off valve and expansion vessel to be discharged. This simplifies checking of the pre-charge pressure, vessel replacement and other servicing operations.

The HERZ design allows the valve to be secured and sealed in the open position. This helps prevent accidental or unauthorised isolation of the expansion vessel from the system and ensures that it remains connected during normal operation.

The body is made from nickel-plated forged brass CW617N according to EN 12165. The full-bore ball is made from CW617N brass and hard chrome plated, the spindle is CW614N brass, the ball seal is PTFE and the spindle seal is EPDM.

HERZ specifies an operating temperature range of −10 to +150 °C; when water is used, the minimum temperature is +0.5 °C and the maximum water temperature is +110 °C. A 25–50% ethylene- or propylene-glycol mixture is also permitted. The valve is intended only for shut-off service and must not be used for flow regulation.

Technical information