Miniature Valves
Until the 70s, the miniature hot steam forged valves were manufactured in countless variants.
On exhibition here are two miniature valves with R1/2" male thread and R3/4" female thread. A male thread describes the external thread and a female thread the internal thread.
Refrigerant Valves
In the past, refrigerant valves like this special valve with a nominal diameter of 50 were manufactured.
This refrigerant valve with hard lead seal was a special design for the Bergedorf Eisenwerke.
Acid-resistant Angle Seat Valves
The acid-resistant angle seat valves symbolise the entry into the chemical industry, for which LESER today supplies safety specialities.
Double Red Brass Feed Valves
The impressive double red brass feed valve, like the injector shown above, was "grabbed" by Leser a few houses away during the demolition of the Deback boiler plant.
Pressure Reducing Valves
The pressure reducing valve type 612 is designed to reduce steam from a high pressure (upstream pressure) to a low pressure (downstream pressure). Pressure reduction is achieved by throttling of the inlet flow at the valve seat by variation of the flow area between seat and disc.
The downstream pressure which is transmitted by the impulse line to the diaphragm counteracts the spring force acting on the valve spindle. Thereby the valve opening corresponds to the spring setting and the required downstream pressure will be obtained. The downstream pressure when set is independent of variations of upstream pressure and also of variation of flow and remains constant.
System Layout with Pressure Reducing Valve Type 612:
Spring-loaded Quickaction Stop Valves
Leser produced quick-action stop valves until the end of the 60s, perhaps even into the 70s. Many parts of the safety valve production of that time were used. The pawl could be released via a cable pull and the valve could be closed via the built-in spring. These valves were used as fast closing and distance operated shut-off valves when filling tanks.
Single-port Springloaded Safety Valves
The single spring safety valve - open design was returned to Leser by Linde in 1979. The valve was in continuous operation for more than 20 years on a two-crank, six-stage high-pressure compressor for 2,200 m³ of air.
Full-lift Nozzle-type Safety Valves
A former exhibit of a nozzle full-lift safety valve with a body made of heat-resistant cast steel.
Spring-loaded Safety Valves
High Pressure Safety Valves
FOOD QUALITY Full-lift Springloaded Safety Valves
Type 448
Production time period from around 1983 to 2002
Connections Tri-Clamp flange – COCO
Data sheet type 448:
Double Springloaded Safety Valves
The double springloaded safety valve was used to protect the pressure of a ship's boiler of the tugboat Woltman.
The tugboat WOLTMAN was built in 1904 at the shipyard of the Sachsenberg brothers in Rosslau an der Elbe on the order of Strom- und Hafenbau for the financial deputation in Hamburg.
Today it is the last sea-going tugboat with steam drive and a coal-fired boiler in Germany.
Historical pictures of the tugboat Woltman:
Spring-loaded In-Line Relief Valves
Type 5341.1792
Production time period 1981 to 2016
As a result of adjustments to the product range, Types 532 and 534 were discontinued when CE approval expired on 31 October 2016. Due to the special design, there was no direct product alternative.
Official statement of production stop:
