PVM 15-50, differential pressure valves

Transcription

1 PVM 15-5, differential pressure valves High accuracy Low pressure drop Quick to install Dimension: DN 15-5 Temperature: -1 C till +12 C Pressure class: PN 2(STV)/PN 25(PV) February 218 Rev.

2 Description PVM DN 15-5 Area of use The differential pressure valves PVM is used to distribute the flow within different areas in heating and cooling systems. The differential pressure valves PVM consists of a differential pressure valve (PV) and a balancing valve (STV). PVM maintains the differential pressure across a circuit, such as a stem, which supplies radiators or to secure differential pressure over a control valve so that good authority is achieved for modulating regulation. The differential pressure held constant, can be adjusted to achieve the prescribed flow. At increased available pressure, the differential pressure valve closes and at reduced pressure, the differential pressure valve opens. The PVM package also includes a shut-off valve so that the circuitry return and return pipes can be closed. Load February 218 Rev.

3 Description PVM DN 15-5 Dimensioning The differential pressure package is determined based on the prescribed flow and available pressure. Example: The prescribed flow rate is 3 l/h and the differential pressure to be maintained is 4kPa. To achieve optimum accuracy and low pressure, try to select a valve package where the prescribed flow is in the center of the chart. Flöde l/s l/h 5 Tryckfallsdiagram diagram/pressure drop diagram PV, DN kpa Δp PV Δp STV ventil kpa kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa 7 kpa 8 kpa Inställning (antal varv från stängd ventil) Settings (number of turns) Calculate the required pressure available ( p req ) at the prescribed flow. p stv + p pv + p load = p req 5,2 + 8,8 + 4 = 54 kpa Then check the required differential pressure p req is available for the circuit. p available p required February 218 Rev.

4 Description PVM DN 15-5 Pre-setting The PVM valve is easy to set on the knob using a 4 mm Allen key. The PV valve is delivered ~ 1 turn open, which corresponds to the lower pressure in its range, for example, 5 kpa for a package that can be adjusted between 5-3 kpa and 2 kpa for packages that can be adjusted between 2-8 kpa. Pre-setting is done by first adjusting the PV valve clockwise to increase the pressure and then counterclockwise to reduce the pressure. See the picture. The adjustment is made with the number of turns required according Lower Δp to the diagram. The flow is verified by measuring the differential pressure across the STV valve. Factory setting PV Pressure range 5-3 kpa Factory setting 5 kpa 2-6 kpa Factory setting 2 kpa 2-8 kpa Factory setting 2 kpa Measuring The PVM is equipped with four measuring sockets for measuring the pressure drop of the valves, available pressure and differential pressure across the load. See the section for troubleshooting. The cover is disassembled on the valve s outlet socket, then the differential pressure can be measured. To measure the differential pressure across the STV valve, open the ball valve on the measuring outlet. Mounting The STV and PV valve have flow direction marked on the valve body. The PV valve is mounted on the return and STV at the inlet. The capillary tube is mounted between the valves and aired before connecting. NOTE! The capillary tube must not be cut. Higher Δp February 218 Rev.

5 Description PVM DN 15-5 Placing Radiatorsystem Below is an example of placement for PVM To ensure differential pressure across a radiator circuit, PVM should be chosen with a pressure range of 5-3 kpa and should be positioned <1 kpa * from the dimensioned radiator valve. p = 5 kpa Pf 3 DN 25 PN 2 C 544 H P L 2 Last/Load 4 P- P+ 1 *Differential pressure for should not exceed 1 kpa and max 15 kpa including dimensioning valve. 1 kpa corresponds to 5 m straight line (supply and return line) at R = 1 Pa / m. February 218 Rev.

6 Description PVM DN 15-5 Placing Control valve To ensure the differential pressure across a control valve, PVM is placed and set so that the authority over the control valve in dimensioning cases never <.5 or in operation never <.25 Pf 2 SV 3 DN 25 PN 2 C 544 H P L Last/Load P- P+ 4 1 Examples in dimensional cases for a circuit: If p load (4) is 15 kpa and p pipe ( ) is 5 kpa. To obtain β> =,5 the control valve should p sv > which gives p sv = 2 kpa. The authority (β ) at full operation is 2 =,5 ( ) The PV valve should then be set to maintain 4 kpa. The differential pressure maintained by PVM must never be> 4 times as large as Δp over the dimensioning control valve. February 218 Rev. ( SV )>SV *4

7 Description PVM DN 15-5 Troubleshooting If the calculated flow is not achieved, the following needs to be done: 1. Connect the meter between measurement socket 1 and 2. Make sure Δpavailable is higher than calculated Δp for Δpstv + Δpload + Δppvm. If it is not higher then available pressure should be increased via eg pump. If the pressure is higher proceed to step Connect the meter between measurement sockets 3 and 4. Check that Δpload is not higher than estimated. If Δpload is as expected, proceed to point Measure the pressure drop across the valve: For the PV valve, connect the meter between measurement sockets 2 & 3. For the STV valve, connect the meter between measuring sockets 1 & 4. If the pressure drop across any of the valves is higher than expected, contact MMA. p stv 1 1 Pf 4 2 DN 25 PN 2 C 544 p available 2 3 P- P+ p load p pvm 3 February 218 Rev.

8 Pre-setting PVM DN 15-5 Flöde/Flow Flow Tryckfallsdiagram/Pressure drop diagram PV, DN kpa Δp across PV the ventil/valve valve kpa kpa 1 kpa 15 kpa 2 kpa 25 kpa 3 kpa Inställning (antal varv från stängd ventil)/setting (number of turns) Flöde/Flow Flow Tryckfallsdiagram/Pressure drop diagram PV, DN kpa Δp across PV the ventil/valve valve kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa Inställning (antal varv från stängd ventil)/settings (number of turns) Flöde Flow Tryckfallsdiagram/Pressuredrop diagram PV, DN kpa Δp across PV the valve ventil kpa kpa 1 kpa 15 kpa 2 kpa 25 kpa 3 kpa February 218 Rev Inställning (antal varv från stängd ventil) Setting (number of turns)

9 Pre-setting PVM DN 15-5 Flöde/Flow Flow.56 2 Tryckfallsdiagram/Pressuredrop diagram PV, DN kpa Δp across PV the ventil/valve valve kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa Inställning (antal varv från stängd ventil) Setting (number of turns) Flöde/Flow Flow Tryckfallsdiagram/Pressuredrop diagram PV, DN kpa Δp PV across the ventil/valve valve kpa kpa 1 kpa 15 kpa 2 kpa 25 kpa 3 kpa Inställning (antal varv från stängd ventil) Setting (number of turns) Flöde / Flow Tryckfallsdiagram / Pressurdrop diagram PV, DN25L 2-8 kpa Δp PV ventil / valve kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa 7 kpa 8 kpa Inställning (antal varv) / Setting [Number of turns] February 218 Rev.

10 Pre-setting PVM DN 15-5 Flöde/Flow Flow Tryckfallsdiagram/Pressurdrop diagram PV, DN kpa Δp across PV the ventil/valve valve kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa 7 kpa 8 kpa Inställning (antal varv från stängd ventil) Settings (number of turns) Flöde/Flow Flow Tryckfallsdiagram/Pressurdrop diagram PV, DN kpa Δp across PV ventil/valve valve kpa kp kpa 3 kpa 4 kpa 5 kpa 6 kpa 7 kpa 8 kpa Inställning (antal varv från stängd ventil) settings (number of turns) Flöde/Flow Flow Tryckfallsdiagram/Pressuredrop diagram PV, DN kpa Δp PV across the ventil/valve valve kpa kpa 3 kpa 4 kpa 5 kpa 6 kpa 7 kpa 8 kpa February 218 Rev Inställning (antal varv från stängd ventil) Setting (number of turns).4

11 Technical data PVM DN 15-5 Pressure class PN 2 (PV PN 25) Max temperaturw Min temperaturw 12 C -1 C Material Brass dezincification, greyiron, stainless steel, PPS 4% glass Gaskets EPDM, HNBR Max.differential pressure 45 kpa Capacity PV Dimension DN 15 DN 15 DN 2 DN 2 DN 25 DN 25L DN 32 Kvs 2,9 2,9 3,5 3,5 4, 8,7 1,1 Area 5-3 kpa 2-6 kpa 5-3 kpa 2-6 kpa 5-3 kpa 2-8 kpa 2-8kPa Flow (l/s),14-,167,28-,278,28-,278,42-,556,167-,583,28-1,167,278-1,389 Flow (l/h) Dimension DN 4 DN 5 Kvs 15,8 16,2 Area 2-8 kpa 2-8 kpa Flow (l/s),833-2,222 1,389-3,194 Flow (l/h) Capacity for measuring valve STV Number of turns DN 15 DN 2 DN 25 DN 32 DN 4 DN 5 1,18,34,48,79 1,2 2, 2,32,6,77 1,32 2,5 3,6 3,45,83 1,3 1,8 2,8 5,2 4,62 1,13 1,5 2,7 4,1 7,6 5,86 1,55 2,3 4,1 6,2 11,9 6 1,17 2,1 3,6 5,9 8,9 16,7 7 1,62 2,9 5, 7,8 12, 21,2 8 2,55 3,85 6,5 9,7 14,7 25, 9 3,15 4,5 7,9 11,5 17,1 28,6 1 3,55 5,1 8,8 13,1 19,5 31,5 February 218 Rev.

12 Product information PVM DN 15-5 Ordering codes RSK - number Article number Desgination Description PVM 15 G15 int thread, 5-3 kpa PVM 2 G2 int thread, 5-3 kpa PVM 25 G25 int thread, 5-3 kpa PVM 15 G15 int thread, 2-6 kpa PVM 2 G2 int thread, 2-6 kpa PVM 25 G25 int thread, 2-8 kpa PVM 32 G32 int thread, 2-8 kpa PVM 4 G4 int thread, 2-8 kpa PVM 5 G5 int thread, 2-8 kpa Dimensions mm Size A B C D E F Weight/kg PVM 15 DN ,24 PVM 2 DN ,31 PVM 25 DN ,6 PVM 25L DN ,34 PVM 32 DN ,92 PVM 4 DN ,62 PVM 5 DN ,85 E D F DN 25 PN 2 C 544 A B C February 218 Rev. We reserve the right to change the products without prior notice.