Multiplying factors for non-standard conditions Condensate pumps Mechanical pumps and pumps traps
9
Filling head
Capacity multiplying factors for non-standard filling heads
mm
inches
-76
(-3")
0.23
-25
(-1")
0.41
0
(0)
0.70
152
(6")
0.89
305 457
(12") (18") (24") (36") (48") (60")
0.95
0.98
610
1.00
914
1.00
1 219
1.08
1 524
1.20
Capacity multiplying factors for motive gas supply (other than steam)
% Back pressure v. Motive pressure (bp/MP)
10% 20% 30% 40% 50% 60% 70% 80% 90%
Capacity multiplying factors
1.19 1.43 1.43 1.53 1.85 2.04 2.14 2.20 2.44
To size the PTF4 in a closed system: Please note that the vent assist valve that is noted in the formula below can be identified by item 23 on page 1. Establish the available motive pressure. Establish the static backpressure on the pump-trap combination. Place the established pressures into the formula below:
- Pump motive pressure – Minimum valve assist valve delta P > Backpressure - Capacity charts to be read as normal, i.e. at pump motive and backpressure. - If, Pump motive pressure – Minimum valve assist valve delta P < Backpressure, then isolate or remove the valve assist valve and multiply the capacity by 0.77 to find the reduced capacity without the valve assist valve. Sizing example: 1 A closed system has the following conditions: Motive steam available = 10.3 bar g (150 psi g). Static backpressure = 3.1 bar g (45 psi g). Open system PTF4 capacity charts show capacity at 10.3 bar g (150 psi g) motive with 3.1 bar g (45 psi g) backpressure. Closed system The vent assist valve on the PTF4 requires at least 5.2 bar g (75 psi g) differential pressure to operate in a closed system. To size the PTF4 pump: Pump motive pressure – Minimum valve assist valve delta P > Backpressure 10.3 bar g (150 psi g) – 5.2 bar g (75 psi g) > 3.1 bar g (45 psi g) As the motive pressure is 10.3 bar g (150 psi g) and the valve assist valve requires a minimum 8.3 bar g (120 psi g) to operate: 5.2 + 3.1 = 8.3 bar g (75 + 45 = 120 psi g), this combination is sized correctly.
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Page 8 of 12
TI-P135-13 CMGT Issue 5
PTF4 Pivotrol ® Pump (patented)
version Dual Mechanism - Pressure Powered Pump
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