0E0-GB Direct Pressure Reducing DOROT valves MAIN FEATURES The pressure reducing valve maintains, by varying its pressure drop, the outlet pressure at a constant value, when inlet pressure or the flow-rate are varying. and flow rate. The pressure redu- The Direct- acting PRV are used: - in water networksto maintain a requested pressure in the supply main. - in sanitary appliances: to maintain the water pressure constantly below the max. permissible value. - in water networks- to save water. By controlling the pressure of the taps, excessive withdrawal of water and is avoided. Undetected eakages are redued. - in compressed air systems: to keep the constant air pressure in the main, regardless of fluctuations in pressure supplied by the compressors; - To reduce and stabilize the pressure in the main, downstream of tanks or storage cylindiners.
GENERA The DOROT pressure reducing valves Series DPR, DPR-F are of the balanced seat type. The inlet pressure, when acting on the two openings A and B with the same section, is compensated, and does not exert any force on the pin-plug system when the degree of valve opening changes. Two forces act on the diaphragm: The outlet pressure creates a force that tends to close the plug, and is topposed by the spring mechanical force that tends to open the plug. This results in the pressure reducing valve acting like a balanced seat type, where the outlet pressure almost- unaffected by variations in inlet pressure. DPR Diaphragm pressure reducing valve with single balanced seat. Ensures min. pressure drops with high flow rates. Downstream pressure set by means of the setting screw () and is locked with lock nut (3) DPR-P ike DPR, but with pressure gauge Ø0 for reading downstream pressure Models DPR-/ /" mm DPR-3/ 3/" 0mm DPR- " mm DPR-/ /" 3mm DPR-/ /" 0mm DPR- " 0mm Models DPR-P-/ /" mm DPR-P-3/ 3/" 0mm DPR-P- " mm DPR-P-/ /" 3mm DPR-P-/ /" 0mm DPR-P- " 0mm SIZING Excessive flow velocity generates too-high pressure drop and noisy performance. ence, it is very important that the valve size will be selected properly, considering the maximal flow rate the valve is supposed to regulate. The diagrams at the right side, allow the selection of the valve size according to the flow velocity, that is caused by the flow rate (bottom axis). It is recommended to select the valve that operates at flow velocity of -m/s (water systems) and 0-0m/s (air systems). /speed diagram DPR,DPR-P,DPR-N,DPR-N-P,DPR-U Speed (m/s) 30 0 0 0, 0, DPR-/ DPR-3/ DPR- DPR-/ DPR-/ DPR- Air Water 0, 0, 0, 0, 0, 0, 0 0 0 0 00 00 00 00 000 m3/h 0 0 00 00 000 000 0000 l/min EXAMPES OF SIZING Example (cavitation- see next page) Operating conditions: Inlet pressure P = bar Outlet pressure P = 3 bar The cavitation diagram indicates that the valve works constantly in the red zone. To avoid rapid deterioration, two valves can be used, connected in serial configuration: Upstream valve: pressure difference to bar (green zone) Downstream valve: pressure difference to 3 bar (green zone). Example (flow rate-see next page) Pressure reducing valve DPR/N with: Inlet pressure (min.) P = bar Outlet pressure P = bar Max. flow rate Q = 0 l/min The flow rate / speed diagram indicates that a diameter of 0 or can should used. The pressure drop diagram (next page) indicates the minimal DP: DPR-3/ Q = 0 l/min DP =. bar DPR- Q = 0 l/min DP = 0. bar /speed diagram DPR-F Speed (m/s) 0, 0, 0, 0, DPR-F- DPR-F-/ DPR-F-3 DPR-F- DPR-F- DPR-F- 0 0 0 0 00 00 00 00 000 DPR-F- 3 0 0 30 0 0 00 00 300 l/s m3/h
CAVITATION The cavitation diagram shows three zones of valve operation in relation to the upstream and downstream pressures, namely: zone C: normal duty, no cavitation zone B: medium duty, possible cavitation zone A: heavy duty, the valve cavitates. Continuous operation in the red cavitation zone causes rapid deterioration of the internal parts. If the pressure reducing valve is to be used in the red zone, please contact DOROT Engineering Department. APPICATION APPROVAS - DVGW approval (Arbeitsblatt W 3) - GA approval (DVR to 3) according to DIN 0 class I (noise below 0 db) - SVGW approval (W/TPW0). - TIN approval (Poland) - CSTB approval (NF P 3-00) (DRV, DRV0). - KTW certification for all materials in contact with water. 3 0 Overall dimensions (mm) DPR / DPR-P Key:.. 3. ock nut. Setting screw.. Diaphragm. Inlet connection. Pin. Plug 0. Guide bushing. Filters. Outlet connection Cavitation diagram A Cavitation zone B Transition zone C Work zone (bar) Inlet pressure 0 0 Plug A 0 0 3 Downstream pressure TECNICA CARACTERISTICS Inlet / outlet connections Diaphragm Seal and O-ring Setting screw and lock nut Filters B bar C (bar) Downstream pressure (outlet). to bar Connections M to M Union connections Downstream pressure adjustment (screw ) Clockwise rotation: increasing pressure Anti-clockwise pressure: decreasing pressure Downstream pressure gauge (DPR-P only) Pressure gauge Ø0, scale 0 to bar Max. operating temperature 0 C Shot-blasted brass OT Shot-blasted brass OT with nylon fabric - diagram [ bar ] 0,0 0, / 3/././ 0 0 0 0 3 0, 0, 0, DPR- DPR-. DPR-/ DPR- DPR-3/ DPR-/ 3 0 0 30 0 0 0 00 00 00 [l/m]
APPICATION APPROVAS - DVGW approval (Arbeitsblatt W 3) - GA approval (DRV/N to DRV3/N) according to DIN 0 class I (noise below 0 db) - CSTB approval (NF P 3-00) (DRV/N, DRV0/N). - KTW certification for all materials in contact with water 3 0 Key:.. 3. Adjusting knob. Setting screw.. Diaphragm. Inlet connection. Pin. Plug 0. Filters. Outlet connection Overall dimensions (mm) DPR-N / DPR-N-P Plug Inlet / outlet connections Diaphragm Seal and O-ring Setting screw Filter TECNICA CARACTERISTICS DPR-N Diaphragm pressure reducing valve with single balanced seat. Ensures min. pressure drop AT high flow rates. Downstream pressure set by means of knob (3) with adjustment scale to bar. DPR-N-P ike DPR-N, but with pressure gauge Ø0 for downstream pressure reading. bar Model DPR-N-/ /" mm DPR-N-3/ 3/" 0mm DPR-N- " mm DPR-N-/ /" 3mm DPR-N-/ /" 0mm DPR-N- " 0mm Model DPR-N-P-/ /" mm DPR-N-P-3/ 3/" 0mm DPR-N-P- " mm DPR-N-P-/ /" 3mm DPR-N-P-/ /" 0mm DPR-N-P- " 0mm Shot-blasted brass OT Reinforced plastic with nylon fabric Downstream pressure (outlet). to bar Connections M to M Union connectors Downstream pressure adjustment (knob 3) Clockwise rotation: increasing pressure Counter-clockwise pressure: decreasing pressure Downstream pressure gauge (DPR-N-P only) Pressure gauge Ø 0, scale 0 to bar Max. operating temperature 0 C - diagram [ bar ] 0,0 0, / 3/././ 0 0 0 0 3 0, 0, 0, DPR-N- DPR-N-/ DPR-N-/ DPR-N- DPR-N-3/ DPR-N-/ 3 0 0 30 0 0 0 00 00 00 [l/m]
APPICATION APPROVAS - ASSE, ANSI, CSA, UPC (USA) approvals 0 3 Special expansion bypass BY-PASS 3 Key:.. 3. Setting screw. ock nut.. Inlet connection. Diaphragm. Valve seat. Outlet connection 0. Filter. Filter cap. Plug 3. Guide bushing. By-pass EXPANSION Plug Inlet connection Diaphragm Seal and O-ring Setting screw and lock nut Filter DPR-U -body valve Models Diaphragm pressure reducing valve, single seated, with spring. Ensures min. pressure drop with high flow rates. Provided with high-capacity filter, having a separate connection for covenient cleaning. Downstream pressure set by means of screw (3). Fitted with by-pass valve, that allows the release of excessive upstream pressure (generated, for example, by thermal expansion of boiler water) to the downstream side. DPR-U-/ /" mm DPR-U-3/ 3/" 0mm DPR-U- " mm DPR-U-/ /" 3mm DPR-U-/ /" 0mm DPR-U- " 0mm Cast iron Nordel with nylon fabric UPSTREAM PRESSURE Overall dimensions (mm) DPR-U PUG REDUCED PRESSURE TECNICA CARACTERISTICS 0 bar Downstream pressure (outlet) Adjustable. to bar Upstream connection M Union connection Downstream connection Female thread Downstream pressure adjustment (screw 3) Clockwise rotation: increasing pressure Counter-clockwise pressure: decreasing pressure Max. operating temperature 0 C - diagram [ bar ] 0,03 0,0 0,0 / 3/././ 03 03 3 3 3 0,0 0, 0, 0, 0, DPR-U- DPR-U-/ DPR-U-/ DPR-U- DPR-U-3/ DPR-U-/ 000 000.000.000 0000 0000 0000 [ l/h ]
APPICATION DPR-F-x-[A/B/C] Flanged pressure reducing valve, single balanced seat and spring. Ensures min. pressure drops with high flow rates. Downstream pressure set by an adjusting bolt Ductile iron body, epoxy coated. DPR-F-x-[A/B/C] Equal to DPR-F, but max. inlet pressure bar. DPR-F0-x-[A/B/C] Equal to DPR-F, but max. inlet pressure 0 bar. PN models: PN models: PN0 models: Class A- Outlet setting.- bar Class A- Outlet setting.- bar Class A- Outlet setting.- bar DPR-F--A " DN0 DPR-F--A " DN0 DPR-F0--A " DN0 DPR-F-.-A." DN DPR-F-.-A." DN DPR-F0-.-A." DN DPR-F-3-A 3" DN0 DPR-F-3-A 3" DN0 DPR-F0-3-A 3" DN0 DPR-F--A " DN00 DPR-F--A " DN00 DPR-F0--A " DN00 DPR-F--A " DN DPR-F--A " DN DPR-F0--A " DN DPR-F--A " DN0 DPR-F--A " DN0 DPR-F0--A " DN0 DPR-F--A " DN00 DPR-F--A " DN00 Class B- Outlet setting - bar Class B- Outlet setting - bar Class B- Outlet setting - bar DPR-F--B " DN0 DPR-F--B " DN0 DPR-F0--B " DN0 DPR-F-.-B." DN DPR-F-.-B." DN DPR-F0-.-B." DN DPR-F-3-B 3" DN0 DPR-F-3-B 3" DN0 DPR-F0-3-B 3" DN0 DPR-F--B " DN00 DPR-F--B " DN00 DPR-F0--B " DN00 DPR-F--B " DN DPR-F--B " DN DPR-F0--B " DN DPR-F--B " DN0 DPR-F--B " DN0 DPR-F0--B " DN0 DPR-F--B " DN00 DPR-F--B " DN00 Class C- Outlet setting - bar Class C- Outlet setting - bar Class C- Outlet setting - bar DPR-F--C " DN0 DPR-F--C " DN0 DPR-F0--C " DN0 DPR-F-.-C." DN DPR-F-.-C." DN DPR-F0-.-C." DN DPR-F-3-C 3" DN0 DPR-F-3-C 3" DN0 DPR-F0-3-C 3" DN0 DPR-F--C " DN00 DPR-F--C " DN00 DPR-F0--C " DN00 DPR-F--C " DN DPR-F--C " DN DPR-F0--C " DN DPR-F--C " DN0 DPR-F--C " DN0 DPR-F0--C " DN0 DPR-F--C " DN00 DPR-F--C " DN00 Plug (ND 0 to 00) (ND to 00) Seal ip seal Seal ring Guide bushings Setting screw and lock nut Finish Ductile iron GS00- Ductile iron GS00- Brass Faced steel Epoxy resins (blue RA 0) TECNICA CARACTERISTICS Downstream pressure (outlet) - - 0 bar (ND00 only up to bar). to bar (standard) to bar (optional) to bar (optional) Downstream pressure adjustment Clockwise rotation: increaseing pressure Counter-clockwise pressure: decreaseing pressure Connections Flanged to UNI3 (NP - - 0) Pressure gauge connections (upstream and downstream) Max. operating temperature G / " ND0 to ND G 3/" ND0 to ND00 0 C
Overall dimensions (mm) - diagram DPR-F [ bar] 0, 0, 0, 0, DN00 DN0 DN DN00 DN0 DN DN0, 0 0 0 00 00 300 00 00 00 000 000 3000 000 [ l/min] 0 0 00 0 00 30 0 30 30 00 0 0 33 0 0 3 3 0 00 3 B PN 00 0 0 30 B PN 00 3 0 300 30 B PN0 00 3 0 300 -- 0 3 Key:.. 3. Plug. Seal.. Seal ring. Guide bushings. ip seal. Setting screw 0. screws