Notes: 1) The highest working pressure p1 within the water circuit and without using the safety shut-off valve RMG 790 is necessary to determine the size of the expansion vessel. This pressure is 0,1 to 0,2 bar under the response pressure pS SBV on the heating station. (Example above: p1 = pS SBV - 0,2 bar = 2,3 bar). 2) The limiting pressure pK on which the control device of the RMG 790 must be set up depends on the response pressure required pS SBV des RMG 790, on the pipe sizes of the main valve and also on the mounting position of the actuator assembly. Reference values for the limiting pressure pK can be taken from the following table:
Limiting pressure pK to be set in bar mounting position of the RMG 790 pipe size
vertical (main valve - top)
vertical (main valve - bottom )
DN 25 DN 50 DN 80 DN 100 DN 150
pS - 0,3 pS - 0,6 pS - 0,7 pS - 0,7 pS - 0,7
pS - 0,4 pS - 0,8 pS - 1,0 pS - 1,0 pS - 1,0
horizontal pS - 0,35 pS - 0,70 pS - 0,85 pS - 0,85 pS - 0,85
Example: For RMG 790, pipe sizes DN 80 in vertical mounting position (main valve at the top): pK = pS SBV - 0,7 bar = 2,3 bar - 0,7 bar = 1,6 bar
3) Addtionally to control such small damages a sensing or a pressure switch can be provided. A sensing switch must be installed at the highest position in the heat exchanger. We recommend that you install a switch with two switch positions. The first switch position can be used to start an alarm and the second one to close the SAV over an additional magnetic valve which is parallel to the control device. (see the following scheme).
2/2 waymagnetic valve
2/2 way magnetic valve for hot water PN 16, DN 13, G 3/8 i protected against explosion, Ex-s G4, currentless open with a connection cable (casted with plastic material) electr. connection
RMG-order-nr.
24 VDC
00 024 149
220 V, 50 Hz
00 024 150
A pressure switch must be installed so that the switch pressure is at least 0,2 bar over the max. working pressure within the water circuit and 0,1 to 0,2 bar under the limiting pressure on which the control device of the RMG 790 is set. 4) We recommend that you apply a second mark on the manometer of the heating station close to the stipulated limiting marks for the response pressure of the safety valve pS SBV .This mark indicates the highest working pressure p2 within the water circuit of the heating station.
790.20 p.06