Pressure relief valve DHV 78 Benefits diaphragm controlled pressure relief valve with piston guidance simple design, reliable function particularly suitable for oscillating pumps constant, frictionless and low vibration control behaviour high reproducibility of the set pressure simple pressure setting possible at any time, also during operation Application chemical plants industrial plants water treatment electroplating plants Intended Use The pressure relief valve which is directly controlled by the medium, is used in technical processing plants for keeping preset working pressures constant on the primary side. The pressure relief valve can also be used as an overflow valve to prevent pressure peaks. In this case, the pressure relief valve is fitted in a bypass line. Pressure relief valves are not safety valves according to the Pressure Equipment Directive. Valve Function When the valve is closed in the position of rest, the diaphragm under the valve seat is only impinged by the low secondary pressure. Any rise in working or primary pressure lifts the diaphragm against the spring force. The valve opens and the pressure decreases. Valve Setting. Remove the protection cap (DN 0 DN 50).. Undo the counter nut on the adjustment screw. 3. Turn the adjustment screw clockwise (pressure increase) until the desired set pressure or opening pressure is reached. Application Media Neutral and aggressive fluids or fluids containing solid particles, provided that the valve components coming into contact with the fluids are resistant at the operating temperature in accordance with the ASVresistance guide. For nitric acid or sulfuric acid please specify the precise operating conditions of the application. Fluid Temperature see pressure/temperature diagram Operating Pressure see pressure/temperature diagram Set Range DN 8 DN 5: 0,5 0 bar DN 0 DN 50: 0,5 8 bar Nominal Pressure (H O, 0 C) PN 0 Working Pressure set pressure plus flow dependent pressure increase (see characteristic curves). Opening Pressure DN 8: 0,5 bar DN 0 50: 0,3 bar Hysteresis Difference between opening and closing pressure approx. 0.3 bar Valve Body DN 8: PVCU, PP or PVDF DN 0 50: PVCU, PP or stainless steel VA Bonnet PP, glass fibre reinforced Diaphragm PTFE ( diaphragm with PTFE coating on the surfaces coming into contact with the medium) Sealing FPM Screws stainless steel (.30) Actuation medium controlled Connection refer comments on the identification numbers Flow Direction always in the direction of the arrow Mounting Position as required Fastening via threaded inserts (metal inserts) in the valve body > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Colour body: PVCU, grey, RAL 70 body: PP, grey, RAL 703 body: PVDF, opaque, yellowishwhite bonnet: orange, RAL 00 valve body: stainless steel, unpainted Attention When the valve is in the position of rest, the counterpressure (secondary pressure) may be approx. times higher than the set pressure pe, the valve remains closed. > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 Ident code Settingrange and option A = standard ident no. ( digits) B = ident code for settingrange C = ident code for»washed free of silicone«a = ident code»0«not washed free of silicone b = Ident code»«washed free of silicone example c = ident no. / setting = 0,5 bar / not washed free of silicone example d = ident no. / setting =,0 bar / not washed free of silicone example e = ident no. / setting = 0 bar / washed free of silicone > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 Pressure/temperature diagram Sectional drawing DHV 78, DN 8 A = primary side B = secondary side = adjustment screw 3 = counter nut 5= diaphragm 7 = valve seat A = primary side B = secondary side = protection cap = adjustment screw 3 = counter nut 5= diaphragm 7 = valve seat P = operating pressure T = temperature The pressure/temperature limits are applicable for the stated nominal pressures and a computed operating life factor of 5 years. These are standard values for harmless media (DIN 03), to which the valve material is resistant. For other media please refer to the ASV resistance guide. The durability of wear parts depends on the operating conditions of the application. > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 Applications A = generation of a constant working pressure B = use at high inlet pressure C = optimal solution for the reduction of pressure surges with overflow valve to protect the system Malfunctions, possible causes, rectification Maintenance note Screw tightening torque (Nm) The specified values apply to lubricated screws. Check the tightening torque of the body screws at certain intervals in case of setting of the diaphragms and/or temperature fluctuations. Operating note Please take into account that the material PTFE is classified as resistant against many media, however, PTFE is not diffusion tight when used as a film, e.g. for the ASV membranes. Please contact us for limit cases (nitric acid or sulfuric acid). > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78, [d] body PVCU size pressure range DN(mm) 8 / PN(bar) 0 Connection sealing ident No. PVCU 7030 socket DIN FPM 7038 0.30 kg body PP size pressure range DN(mm) 8 / PN(bar) 0 Connection sealing ident No. PP 70 socket DIN FPM 78 0.30 kg body PVDF size pressure range DN(mm) 8 / PN(bar) 0 Connection sealing ident No. PVDF 70 socket DIN FPM 7 0.30 kg > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78, [d] dimensions DN(mm) 8 / dimensions(mm) d H h L L L3 M v 0 0 9 85 9 M 5 3 > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78, [d d3] body PVCU size 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 Connection sealing ident No. PVCU 703 703 7033 703 7035 703 7037 socket DIN FPM 7039 700 70 70 703 70 705 PVCU spigot fix DIN 0. kg 889 0.58 kg 0. kg 890 0.58 kg PVCU 70 707 708 709 7050 705 705 socket ANSI FPM 7053 705 7055 705 7057 7058 7059. kg 0.5 kg PVCU 707 7075 707 7077 7078 7079 7080 socket JIS FPM 708 708 7083 708 7085 708 7087 0. kg 0.5 kg PVCU 78 79 730 73 73 733 73 female thread Rp FPM 735 73 737 738 739 70 7 0. kg 0.5 kg PVCU 757 758 759 70 7 7 73 female thread NPT FPM 7 75 7 77 78 79 770 0. kg.97 kg PE 7 77 78 79 70 7 spigot DIN FPM 7 73 7 75 7 77 0. kg A.57 70 703 70 705 70 707 708 female thread Rp FPM 709 70 7 7 73 7 75 GFR flange DIN PP / steel flange ANSI 0.70 kg 0.73 kg 7 0.79 kg 78.05 kg.35 kg 89. kg.3 kg.3 kg.35 kg.38 kg.3 kg.5 kg 73.55 kg 79.8 kg.0 kg 89. kg.0 kg. kg.0 kg. kg. kg. kg 7. kg 750.5 kg 3. kg 893 3.39 kg 3. kg 3. kg 3. kg 3.5 kg 3.7 kg.0 kg 75.05 kg 75.50 kg 3. kg 89 3.3 kg 3.8 kg 3.7 kg 3. kg 3.70 kg 3.7 kg.0 kg 7.0 kg 75.58 kg 3.85 kg 895 3.37 kg 3.90 kg 3.89 kg 3.9 kg 3.9 kg.03 kg.8 kg 77.38 kg 753 5.7 kg > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78, [d d3] body PP size 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 Connection sealing ident No. PP 7 7 73 7 75 7 77 socket DIN FPM 79 770 77 77 773 77 775 0.5 kg 0.57 kg PP 77 777 778 779 780 78 spigot DIN FPM 78 783 78 785 78 787 PP spigot fix DIN GFR flange DIN PP / steel flange ANSI 899 0.5 kg 0.3 kg 900 0.5 kg 70 0.73 kg 708.00 kg PP 788 789 790 79 79 793 79 female thread Rp FPM 795 79 797 798 799 700 70 0.5 kg 0. kg.0 kg. kg 90.09 kg 703. kg 709.7 kg.0 kg. kg.8 kg 90.0 kg 70.5 kg 70.0 kg. kg 3. kg 3.3 kg 903.95 kg 705 3.3 kg 7.08 kg 3.9 kg 3. kg 3.7 kg 90.9 kg 70 3.70 kg 7.8 kg 3. kg 3.0 kg 3.5 kg 905.97 kg 707 3.9 kg 73.75 kg 3. kg body A.57 size 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 Connection sealing ident No. A.57 female thread Rp A.57 female thread NPT 7.70 kg 77.70 kg 73.0 kg 77.0 kg 7 9.0 kg 773 9.0 kg 75.0 kg 77.0 kg 7.70 kg 775.70 kg 77.0 kg 77.0 kg 78.0 kg 777.0 kg > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78, [d d3] dimensions DN(mm) 0 3/8 0 5 / 5 0 3/ 3 5 0 3 / 50 0 / 3 50 dimensions(mm).57 PP/PVCU.57 PP/PVCU PP PVCU GFR PP / steel GFR PP / steel GFR PP / steel GFR PP / steel d Rp NPT H H h h L L L L L3 L t d d D D K K M b b l N v 3/8 5 77 5 0 M 8 0 0 / 5 77 5 50 8 30 0 95 89 5 0.3 M 3 3 8 0 5 3/ 75 07 37 80 30 50 5 7 9 0 98 75 9.8 M 5 3 07 3 75 07 37 80 70 30 50 5 7 08 85 79. M 07 0 / 7 77.5 57 30 33 395 0 8 7 00 88.9 M 8 8 7 5 50 / 9.5 77 30 57 30 338 395 0 3 8 5 7 0 98. M 8 8 8 7 5 3 7.5 77 35 57 50 33 395 0 38 8 9 5 5 0. M 8 9 8 7 5 > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 Item Overview DN 8, PVCU, PP, PVDF DN0DN50, PVCU, PP position 5.. 7 9 0 3 8 9 0 quantity designation valve body bonnet pressure plate spring plate pressure spring pressure spring steel ball diaphragm socket head cap screw washer hexagon nut hexagon nut hexagon bolt Oring union end union nut position 3 5 7 8 9 0 3 5 7 8 9 0 quantity designation valve body bonnet diaphragm disc pressure plate spring plate pressure spring steel ball steel ball diaphragm hexagon bolt hexagon bolt hexagon nut hexagon nut washer washer hexagon bolt protection cap Oring union end union nut protection cap protection cap > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 DN0DN50, A (.57) position 3 5 7 8 9 0 7 quantity designation valve body bonnet diaphragm disc pressure plate spring plate pressure spring steel ball steel ball diaphragm hexagon bolt hexagon nut washer hexagon bolt protection cap protection cap > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 Characteristic curves Pressure loss curve (standard values for HO, 0 C) Operating behaviour ΔP = pressure loss Q = flow Pressure loss and kv The diagram shows the pressure loss in relation to the flow Q. Conversion aid: cv = kv x 0.07; fv = kv x 0.0585 Units: kv [l/min]; cv [gal/min] US; fv [gal/min] GB pe = set Pressure pö = opening pressure ps = closing pressure pö ps = hystersis pe pa = flow dependent pressure reduction Q = flow Configuration example The valve is set tight at 5 bar. A flow of approx. 000 l/h is reached at a pressure increase of bar. According to the curve, this results in the following values: set pressure pe: 5 bar; working pressure pa: bar; opening pressure pö: 5.5 bar; closing pressure ps: 5 bar > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 DN 8 DN 0 Q = flow DN 0 Q = flow DN 5 Q = flow DN 5 Q = flow DN 3 Q = flow Q = flow (HO, 0 C) > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com
Pressure relief valve DHV 78 DN 0 Q = flow (HO, 0 C) DN 50 Q = flow (HO, 0 C) > data sheet no.: 3305 03// IPS Flow Systems l Seaham Grange Industrial Estate l Seaham l Co Durham l SR7 0PT l Tel: 09 5 3 l www.ipsflowsystems.com