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All new deadspace free Safety Relief Valve


Head R&D, Handtmann Armaturenfabrik

The Handtmann Armaturenfabrik, Biberach/Riss, Germany is a well-known manufacturer of PED and ASME certified safety relief valves for the beverage and food industries, as well as for the pharmaceutical and cosmetics industries.

Safety relief valves are used in many areas of the food and beverage industries. They are applied in the cold block area, especially in the yeast, storage and fermenting area to protect vessels against overpressure and overfilling. Also, they are suitable for tank pressure regulation. Besides the strong focus on a safe process, the hygienic design is fundamental to prevent bacterial contamination of the equipment and the medium.


To prevent overpressure in the tank, various solutions are possible. Safety relief valves have proven to be an excellent solution. They are either suitable for pressure relief or, if used as a bunging device, for pressure control.

The original purpose of a bunging device is the regulation of the fermentation process. Bunging devices are either weight or spring-loaded safety relief valves for gas only, with an optional bunging glass filled with liquid. The objective is to adjust the required CO2 content in beer and to hold the fermentation pressure in the bright beer tank at a constant level.


During the production process, pressure increases in various operating steps. This always happens when a fluid (liquid or gas) is applied to a closed system, or when gas is being released during the fermentation process. If a pressure increase occurs, the emerging fluid must be removed. Otherwise, the tank could be severely damaged or even burst, when the tank design pressure is being exceeded.

Possible causes of a pressure increase within the tank are:

  • Preloading the tank with gas/CO2
  • Filling/overfilling with liquid
  • Release of gas during the fermentation process
  • Malfunction of the valve during various operating conditions

The main objective for tank top solutions is to ensure a high standard of both — an efficient protection against over and under-pressure as well as an uncomplicated CIP. Therefore, the safety relief valve is usually combined with a vacuum valve and a CIP-system on a tank top plate, or an RLV (cleaning-air-valve combination). The RLV has the advantage of combining all three functions while only requiring just one tank connection.

Basic requirements are the reliable cleaning of the valves seats and the possibility to lift the valves on a regular basis, in order to check the smooth operation.

When designing safety relief valves as per various requirements and guidelines the following topics are important:

  • Type of fluids – water/liquids, air/CO2
  • Performance of the filling pump – in case of a pump failure the derived volume flow
  • Operating pressure – working pressure during standard operating status
  • Set pressure – switch function of the valve
  • Tank design pressure – maximum tank working pressure
  • Guidelines, norms – ASME, PED

Handtmann Armaturenfabrik with all new Safety Relief Valve type 33503/33603

Basis for the design and sales of safety relief valves on the European market are the requirements of the PED, as well as various EN DIN norms. For decades, the safety relief valve technique from Handtmann has proven worthwhile in this field. With regard to overpressure protection of tanks, materials, and clean ability the high-quality valves offer an optimal solution for all applications.

Armaturenfabrik now present an all new safety relief valve type 33503/33603 in hygienic design for processes with extremely high requirements to clean ability. These new valves of sizes DN 40 – DN 80 are distinguished by the dead-space free construction of their inlet area. Thus, a most effective cleaning is guaranteed.

Optionally available will be a pneumatic lifting device, as well as an electric reply for the open valve position.

The valves are suitable for various hygienic processes, such as protection of plants and vessels in the

  • brewing and beverage industries
  • food industry
  • dairy industry
  • pharmaceutical industry
  • cosmetics industry
  • medical technology

as well as for all kind of hygienic processes where vessels with liquids, steam and/or gases must be protected against overpressure.

The safety relief valves No. 33503/33603 are most suitable for the installation in a top flange. Due to the dead-space free design an additional CIP bypass is no more necessary. Besides the outstanding clean ability, another benefit for our customers is the availability of two optional inlet and outlet connections: Either welding ends or hygienic flanges.