The Pivotrol Pump Patented Selection and Sizing

Transcription

1 How to Select and Size From the inlet pressure, back pressure and filling head conditions given below, select the pump size and check valve package which meets the capacity requirement of the application. Specify pump body, type PTC or PTF. Select optional extras as required. For GPM, multiply the capacities below by.2. For kg/h, multiply the capacities below by.454. For liquid specific gravities from.9 to.65, consult Spirax Sarco. * Back pressure is the lift height (H) in feet x.433 plus in return line, plus downstream piping friction pressure drop in calculated based on the maximum instantaneous discharge rate of te respective pump selected. (See TIS Sheets) Note: To achieve rated capacity, pump must be installed with check valves supplied by Spirax Sarco. Use of a substitute check valve may effect the performance of the pump. Capacity lb/h When installed with recommended filling head above top of pump. load Steam pressure available for operating pump Vertical lift from pump to the return piping 3 feet in the return piping (piping friction negligible Filling head on the pump available 7 lb/h inches Solution: 1. Calculate "H", the totallift or back pressure, against which the condensate must be pumped. = (3 x.433) + 25=38 2. From capacity table, with 8 inlet pressure and 4 back pressure, choose a 2" x 2" pump with stainless steel check valves, which ha a capacity of 6,935 lb/h. Note from capacity multiplying factor charts: A. Pump capacity if filling head is 24": 1.16 x 6,935 = 845 lb/h B. Pump capacity using compressed air: 1.12 x 6,935 = 7767 lb/h (% back pressure is 38 75=5%) Vent to atmosphere Pump Exhaust Motive Steam or Gas Supply Return Return Line At least 12" Seal on overflow Vented Receiver (open system) Filling Height Filling Head Powered Pump TD 42L or 52L Trap when steam supply is used Recommended Installation The pump is fitted with vented receiver or an inlet reservoir. Details of the application will determine whether a vented receiver or an inlet reservoir will be needed to accomplish this. 594 TI-5-3-US 7.15

2 Vented Receiver (Open System) To drain condensate from a single or multiple source an "open" system, a vented receiver should be installed in a horizontal plane above and ahead of the pump. Sufficient receiver volume is needed above the filling head level to accept the condensate reachng the receiver during the pump discharge stroke. More important, the receiver must be sized to allow sufficient area for complete flash steam separation from the condensate. The chart below shows proper vented receiver sizing (per criteria set forth in the A.S.H.R.A.E. Handbook) based on the amount of flash steam present. If the receiver is sized as shown below, there will be sufficient volume for condensate storage and sufficient area for flash steam separation. The receiver can be a length of large diameter pipe or a tank. Pump size - up to 3"x 2" Flash Steam Pipe Size Vent Line up to Diameter Length Diameter 75 lb/h 4" 36" 1-1/2" 15 lb/h 6" 36" 2" 3 lb/h 8" 36" 3" 6 lb/h 1" 36" 4" 9 lb/h 12" 36" 6" 12 lb/h 16" 36" 6" 2 lb/h 2" 36" 8" The Pivotrol Pump Patented Inlet Reservoir Piping (Closed System) To drain condensate from a single piece of equipment in a "closed" system, a reservoir should be installed in a horizontal plane above and ahead of the pump. Sufficient reservoir volume is needed above the filling head level to accept the condensate reaching the reservoir during the pump discharge stroke. The chart below shows minimum reservoir sizing, based on condensate load, needed to prevent equipment flooding during the pump dischare stroke. The reservoir can be a length of large diameter pipe or a tank. Pump size - up to 3"x 2" Liquid Reservoir Pipe Size lb/h 3" 4" 6" 8" 1" 5 or Less , , Pump Size PTF4 Flash Steam Pipe Size Vent Line up to Diameter Length Diameter 1 lb/h 16" 6" 6" 2 lb/h 2" 6" 8" 3 lb/h 24" 6" 8" 4 lb/h 26 6" 1" 5 lb/h 28" 6" 1" 6 lb/h 3" 72" 12" 7 lb/h 32" 72" 12" 8 lb/h 36" 72" 14" Pump Size PTF4 Liquid Load Reservoir Pipe Size* lb/h 12" 16" 2" 24" 1, , , , , 9 6 6, 9 6 * When BP/MP is less than 5%, these reservoir lengths can be reduced by 1/2. Capacity Multiplying Factors for other Filling Heads Filling Head Check valve and piping size, pump type Inches mm 2" x 2" PTC/PTF 3" x 2" PTC/PTF PTF-HP PTF NA NA NA N/A N/A Capacity Multiplying Factors for Motive Gas Supply (other than steam) 2" and 3" x 2" PTC / PTF 1% 2% 3% 4% 5% 6% 7% 8% 9% PTF-HP PTF % Back VS. Motive (bp / MP) Capacity Multiplying Factors Capacity Multiplying Factors Capacity Multiplying Factors TI-5-3-US

3 Motive Back 2" x 2" PTC/PTF 12" Filling Head lb/hr The Pivotrol Pump Patented 3" x 2" PTC/PTF 3" x 3" PPF Top 12" Filling Head lb/hr 3" x 2" PTF-HTF 12" Filling Head lb/hr Motive Back 3" x 2" PTF-HP 12" Filling Head lb/hr TI-5-3-US 7.15

4 PTF4 The Pivotrol Pump Patented Motive Back 36 Fill Head (7 Fill Height) lb/hr To size the PTF4 in a closed system: Establish available motive pressure. Establish static back pressure on Pump/Trap combination. Place established pressures in formula below: Pump Motive () min. VAV delta P () > Back () Capacity charts to be read as normal, i.e. at pump motive and back pressure. If, Pump Motive () min. VAV delta P () < Back (), then isolate or remove VAV and multiply capacity by.77 to find reduced capacity without VAV. Sizing Example: 1 A closed system has the following conditions: Motive steam available = 15. Static Back = 45. Open System. PTF4 Capacity charts show capacity at 15 motive with 45 back pressure. Closed System. The Vent Assist Valve on the PTF4 requires at least 75 differential pressure to operate in a closed system. To size the PTF4 pump: Pump Motive min. VAV delta P > Back > 45 As the motive pressure is 15 and the VAV requires a minimum 12 to operate ( = 12), this combination is sized correctly. TI-5-3-US

5 Capacity Charts 2" x 2" Pivotrol Pump 1 PSIG Back (23ft) PSIG Back (46ft) PSIG Back (69ft) PSIG Back (92ft) PSIG Back (116ft) 8 Motive PSIG PSIG Back (139ft) 8 PSIG Back (185ft) 1 PSIG Back (231 ft) 12 PSIG Back (277 ft) Motive PSIG PSIG Back Pr essure (323 ft) (1) (2) (3) (4) (5) (6) (7) (8) (9) (1) (11) (12) (13) (14) (15) (16) (17) (18) (19) (2) (21) (22) (23) (24) 3 PSIG Back (69ft) 6 PSIG Back (139ft) (23ft) PSIG Back (46ft) 1 PSIG Back 2 4 PSIG Back (92ft) 5 PSIG Back (116ft) " x 2" Pivotrol Pump lb/hr (GPM) Motive PSI G PSIG Back (185ft) 1 P SIG Back (231 ft) 12 PSIG Back Motive PSI G PSIG Back (323 ft) (277 ft) PSIG Back Pre sure (37 ft) (4) (5) (6) (7) (8) (9) (1) (11) (12) (13) (14) (15) (16) (17) (18) (19) (2) (21) (22) (23) (24) (25) (26) (27) (28) (29) (3) (31) (32) (33) (33) (34) lb/hr (GPM) TI-5-3-US 7.15

6 PTF4 Capacity Chart Motive PSIG , 16, 18, 2, 22, 24, 26, 28, 3, 32, 34, 36, Capacity, lbs/hr 38, 4, 42, 44, 46, 48, 5, 52, TI-5-3-US

7 3" x 2" PTF-HP Pivotrol Pump MOTIVE PRESSURE (PSIG) PSIG Back (23ft) 2 PSIG Back (46ft) 4 PSIG Back (92ft) 6 PSIG Back (139ft) 8 PSIG Back (185ft) 1 PSIG Back (231ft) 12 PSIG Back (277ft) 16 PSIG Back (37 ft) 14 PSIG Back (323ft) 18 PSIG Back (416 ft) 2 PSIG (462 ft) 1, 2, 4, 6. 8, 1, 12, 14, 16, 18, 2, 22, 24, 26, 28, 3, (2) (4) (8) (12) (16) (2) (24) (28) (32) (36) (4) (44) (48) (52) (56) (6) (GPM) CAPACITY (lb/hr) Pivotrol Steam Consumption Chart PTC / PTF without insulation PTC / PTF with insulation PTF4 without insulation PTF - HP without insulation PTF4 with insulation PTF - HP with insulation Steam used per 1lbs water Back () TI-5-3-US 7.15

8 TI-5-3-US 7.15 Spirax Sarco, Inc. 215 Spirax Sarco, Inc., 115 Northpoint Blvd, Blythewood, SC 2916 Telephone: (83) FAX (83)