Pressure relief valve DHV 7 set range: 0,5-0,0 bar Advantage pressure setting possible at any time, also during operation optimum monitoring valves high reproducibility of the set pressure high level of operating safety and long service life constant, low vibration control low-maintenance can be easily connected to the pipework by proven technologies - solvent or fusion welding metal inserts in the valve body allow the valves to be directly fitted to mounting sets, the movability of the union nuts remains unaffected reliable diaphragm fastening with standard stainless steel screws hermetically sealed by valve diaphragm with formed sealing rings short face-to-face dimension of the threaded variant Application chemical plants industrial plants water treatment 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. Valve Function When the valve is closed in the position of rest, the piston and/or valve seat is only impinged with the secondary pressure, when it is available. When the working or inlet pressure (primary side) rises above the set value, the diaphragm is lifted against the spring force. The valve opens and a pressure relief on the secondary side takes place. The ribbed diaphragm, dimensioned for full valve lift, separates the medium in the valve body from the bonnet and the atmosphere. The hermetic seal - especially in the higher temperature range - is ensured by formed sealing rings. Valve Setting Set or adjust the desired or permissible working pressure at the adjustment screw with the aid of pressure gauges (ASV diaphragm pressure gauge guard, type MDM 90) in the pipe system after removing the protection cap. The adjustment screw is secured by a counter nut and can be sealed against unauthorized adjustment, if necessary. Flow Media Technically pure, neutral and aggressive fluids, provided that the selected valve materials coming into contact with the media are resistant at the operating temperature according to the ASV-resistance 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 0.5-0.0 bar Nominal Pressure (H O, 0 C) PN 0 Working Pressure set pressure plus flow dependent pressure increase (see characteristic curves). Opening Pressure Difference ca. 0. bar Hysteresis Difference between opening and closing pressure approx. 0.3 bar Valve Body PVC-U PP PVDF Bonnet PP, glass fibre reinforced Diaphragm PTFE (EPDM diaphragm with PTFE coating on the surfaces coming into contact with the medium) Sealing FPM EPDM Screws stainless steel (.30) Actuation medium controlled (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Connection union DIN 803 union socket end for solvent welding DIN ISO (PVC-U) union socket end for fusion welding DIN ISO (PP) union socket end for fusion welding DIN ISO (PVDF) spigot end for solvent welding DIN ISO (PVC-U) fusion spigot end DIN ISO (PP) fusion spigot end DIN ISO (PVDF) union socket end for fusion welding DIN ISO (PP) on request union socket end for fusion welding DIN ISO (PE) on request Flow Direction always in the direction of the arrow Mounting Position as required Fastening via threaded inserts (metal inserts) in the valve body Colour body: PVC-U, grey, RAL 70 body: PP, grey, RAL 703 body: PVDF, opaque, yellowish-white bonnet: orange, RAL 00 bottom section: PVC-U, grey, RAL 70 bottom section: PP, grey, RAL 703 bottom section: PVDF, opaque, yellowish-white Pressure Gauge Connection The pressure relief valve can be factory fitted with a pressure gauge for neutral media. The resistance of the pressure gauge material has to be taken into consideration for other media. The pressure gauge is normally connected to the primary side. (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 Pressure/temperature diagram Pressure loss curve (standard values for H O, 0 C) P = pressure loss pressure loss and k v value The diagram shows the pressure loss P in relation to the flow Q. Conversion aid: c v = k v x 0.07; f v = k v x 0.0585 Units: k v [l/min]; c v [gal/min] US; f v [gal/min] GB Operating behaviour 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. For temperatures below 0 C (PP < +0 C) please specify the precise operating conditions of the application. The rated pressure depends on the valve size and material. For the corresponding rated pressure value of the valve, please refer to the»order table«. pe = set Pressure pö = opening pressure ps = closing pressure pö - ps = hystersis pe - pa = flow dependent pressure reduction (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 Sectional drawing DHV 7 DHV 7 with pressure gauge A = primary side B = secondary side = protection cap = adjustment screw 3 = counter nut = piston 5= diaphragm = flat sealing ring 7 = valve seat The pressure relief valve can be factory fitted with a pressure gauge for neutral media. The resistance of the pressure gauge material has to be taken into consideration for other media.. (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 Applications for Pressure Relief Valve Example : Constant system pressure Applications for Pressure Relief Valve Example 3: Pressure relief valve as backflow preventer X = valve opens Y = valve closed pp = pump pressure pö = opening pressure Applications for Pressure Relief Valve Example : Consumer and/or opens, pressure relief valve closes X = valve opens Y = valve closed pmax = max. pressure pp = pump pressure pö = opening pressure Applications for Pressure Relief Valve Example : Pressure relief valve as overflow valve:the container pressure or system must not exceed the max. pressure value X = valve opens Y = valve closed pp = pump pressure pö = opening pressure X = valve opens Y = valve closed pp = pump pressure pö = opening pressure (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 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 Safe operation of the valve can only be ensured if it is properly installed, operated, serviced or repaired by qualified personnel according to its intended use while observing the accident prevention regulations, safety regulations, relevant standards, directives/technical regulations or codes of practice such as e.g. DIN, DIN EN, DIN ISO and DVS*. *DVS = German Welding Society The intended use includes adhering to specified limit values for pressure and temperature, as well as checking the resistance. This requires all components coming into contact with the medium to be "resistant" in accordance with the ASV resistance guide. Pressure gauge version If the valve body is equipped with a pressure gauge, do not tighten the pressure gauge with more than max. 3 Nm. 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). (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 body PVC-U size d(mm) 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 DN(inch) 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 setting range (bar) 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 Connection sealing ident No. PVC-U EPDM 90 903 90 905 90 907 908 socket end DIN ISO FPM weight 909 0.7 kg 9050 0.7 kg 905.57 kg 905. kg 9053.0 kg 905.8 kg 9055.8 kg PVC-U EPDM 9 95 9 97 98 99 970 spigot end DIN ISO FPM weight 97 0.80 kg 97 0.85 kg 973.8 kg 97.90 kg 975 5.00 kg 97 5.0 kg 977 5.0 kg body PP size d(mm) 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 DN(inch) 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 setting range (bar) 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 Connection sealing ident No. PP EPDM 905 9057 9058 9059 900 90 90 socket end DIN ISO FPM weight 903.0 kg 90.07 kg 905. kg 90.5 kg 907 5.5 kg 908 5.55 kg 909 5.5 kg PP EPDM 978 979 980 98 98 983 98 spigot end DIN ISO FPM weight 985 0.7 kg 98 0.7 kg 987.57 kg 988. kg 989.0 kg 990.8 kg 99.8 kg (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 body PVDF size d(mm) 0 5 3 0 50 3 pressure range DN(mm) 0 5 0 5 3 0 50 DN(inch) 3/8 / 3/ / / PN(bar) 0 0 0 0 0 0 0 setting range (bar) 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 0.5-0 Connection sealing ident No. PVDF socket end DIN ISO PVDF spigot end DIN ISO FPM weight FPM 9077.0 kg 999 9078.07 kg 000 9079. kg 00 9080.5 kg 00 908 5.5 kg 003 908 5.55 kg 00 9083 5.5 kg 005 (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 dimensions d(mm) DN(mm) DN(inch) 0 3/8 0 5 / 5 0 3/ 3 5 0 3 / 50 0 / 3 50 dimensions(mm) PP/PVC-U PVDF PP/PVC-U PVDF PP/PVC-U PVDF d h h L L L L3 L3 t H N V 5 0 8 7 8 0 0 5 0 8 7 8 0 5 37 3 7 50 7 5 53 9 0 07 3 37 3 7 50 7 5 53 0 07 0 57 5 05 00 07 7 5 50 57 5 05 00 07 3 7 5 3 57 5 05 00 07 38 7 5 (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 Item Overview position 3 5 7 8 9 0 3 5 7 8 9 3 5 7 9 quantity designation valve body bonnet separating disc pressure disc diaphragm pressure plate spring plate pressure spring steel ball piston piston point disc steel ball hexagon nut O-ring protection cap hexagon nut disc union end union nut protection cap protection cap disc Plug position 3 5 7 8 9 0 3 5 7 8 9 0 3 5 7 9 quantity designation valve body bonnet separating disc pressure disc diaphragm pressure plate spring plate pressure spring steel ball piston piston point disc steel ball hexagon nut O-ring protection cap hexagon nut disc union end union nut protection cap protection cap disc Plug (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 Characteristic curves 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. bar; closing pressure ps: 5. bar DN 0 DN 0 DN 5 DN 5 (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0
Pressure relief valves, Pressure relief valve DHV 7 DN 3 DN 0 DN 50 (08) 9 00 (08) 837 7800 (03) 935 3900 (0) 350 800 (07) 380 9500 07/0