Spirax Sarco APT10-2, Installation And Maintenance Instructions Manual, Page: 4 / 32

IM-P612-18 ST Issue 3
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2. Product information
Description
The Spirax Sarco automatic pump trap is a displacement receiver pressure rated to PN10. The unit
is capable of automatically trapping or pumping, depending on line conditions. The unit is operated
by steam and is used to remove condensate from process and heating plant under all pressure
conditions including vacuum.
Sizes and pipe connections
Size DN20 x DN20
Fluid connections
Inlet Outlet Motive / Exhaust
DN20 (¾") DN20 (¾") DN15 (½")
BSP - BS 21 parallel BSP
NPT NPT
Limiting conditions
Body design conditions PN10
Maximum motive inlet pressure 2.0 bar g (29 psi g)
Maximum operating pressure 2.0 bar g (29 psi g)
Maximum back pressure 1.9 bar g (27 psi g)
Maximum operating temperature 133°C (271°F)
Minimum operating temperature -10°C (14°F)
Designed for a maximum cold hydraulic test pressure of: 15.0 bar g (217 psi g)
Minimum installation head (from base of pump) 0.2 m (8")
Recommended minimum installation head (from base of pump) 0.3 m (12")
Technical specification - Nominal capacities
For full capacity details for a specific application consult Spirax Sarco.
To accurately size the pump trap, the following data is required.
1. Installation head available, from the base of the pump trap to the centre line of the heat exchanger/
process condensate outlet (m). If the outlet is mounted vertically, then this should be from the
base of the pump to the face of the outlet.
2. Motive steam pressure available to power the pump trap (bar g).
3. Total back pressure in the condensate return system (bar g). See note below.
4. Heat exchanger full load operating pressure (bar g).
5. Heat exchanger maximum steam load (kg/ h).
6. Minimum temperature of secondary fluid. (°C).
7. Maximum controlled temperature of secondary fluid (°C).
Size DN20 x DN20
Pump discharge/ cycle 2.1 litres
1 metre installation head
Maximum trapping capacity 735 kg / h
At: 2.0 bar g (29 psi g) motive
0.5 bar g (7 psi g) total back pressure
Maximum pumping capacity 405 kg /h
Note: Total lift or back pressure BP (static head plus pressure head in the return system) must be
below the motive fluid inlet pressure to allow pump capacity to be achieved.
BP (back pressure) = (H x 0.0981) + (P) + (Pf)
Height (H) in metres x 0.0981 plus pressure (P) bar g in the return line, plus downstream piping
friction pressure drop (Pf) in bar.
(Pf can be ignored if the downstream pipework is less than 100 metres to a non-flooded condensate
return and has been sized to take into account the effect of flash steam at the heat exchanger's full
load operating conditions.)