U N I T E H a.d.   Smederevo, Serbia and Montenegro







screw compressor


piston compressors

low pressure

engineering plants



 Stop valves PN 25/40  
 for working temperatures 40C 450C 
v5.JPG (11799 bytes) v5.JPG (11799 bytes)


Stop valves are designed taking fully into consideration all general and specific norms JUS, DIN, GOST. Technical solution of passing housing profile, stainless steel working parts and sealing method ensure the following:

        minimum local resistance to the flow of fluids

        minimum pressure drop

        easy handling at opening and closing of the valves

        reliable sealing during exploitation of the valves



Material choice is also based on general and specific norms pertaining to material JUS, DIN, GOST. Following materials are used in production of casting iron valves:

- CS 1330 (GS-C25 and GS-Ck24) for housing, cover and sealing shell of the valve

- C.4172 (WNr 1.4021) for spindle

- C.3230 for screws and nuts

- mesing or brass for guiding shell

- sealing material is based on graphite


C.4574 (WNr 1.4571, i.e. WNr 1.4581) is used in production of stainless steel valves.



 High technical requirements in parts production as well as technological execution fully supervised by quality control ensure that quality of final product is in compliance with JUS ISO 9001. After assembly, valves undergo final hydraulic tests, as required by norms, for opening and closing at pressure of 4,0 and 6,0 Mpa. If test results are satisfactory, a test certificate is issued, signed by trained test test engineer.



The valves are intended to be used with liquid and gas fluids (water, steam, gases, ) under pressures up to 4,0 Mpa and at maximum working temperatures of 450C. They can also be used with liquid and gas aggressive fluids for given operation conditions and they are then made of stainless steel and materials resistant to aggression. At assembly, valves are put into working position, in the direction of arrows on the housing. This should correspond to the direction of fluid flow within the system. By placing suitable gaskets with necessary number of screws between valve flanges and system flanges and by tightening the nuts, reliable position, adequate sealing and valve functioning  are ensured. Valve dimensions and installation measures are given in the table.