The Spirax Sarco APT10-4.5 steam-operated automatic pump trap is a condensate recovery unit with a threaded DN20 connection and a ductile iron pump body. It is steam-operated and requires no electrical power. The unit supports automatic trap or pumping operation, with a maximum motive pressure and maximum operating pressure of 4.5 bar g, and is certified in accordance with the ATEX Explosive Atmospheres Directive. It is designed for low installation heights, vacuum conditions, or low differential pressure applications, effectively addressing condensate accumulation in steam-heated equipment under varying loads.
APT10 Automatic Condensate Pump, Three-Quarter Side View | Spirax Sarco
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APT10-4.5 Steam-Operated Automatic Pump Trap | Spirax Sarco
Steam-operated condensate recovery pump for low differential pressure and vacuum conditions
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Specifications
- Operating Mode
- Automatic condensate drainage or water pumping, steam-powered, no electricity required
- Design Pressure Rating
- PN10
- Maximum Motive Pressure
- 4.5 bar g
- Maximum Operating Pressure
- 4.5 bar g
- Maximum Backpressure
- 4.0 bar g
- Operating Temperature Range
- -10°C to 155°C
- Ambient Temperature Range
- -10°C to 200°C
- Cold Hydrostatic Test Pressure
- 15.0 bar g
- Pump Body Material
- Ductile iron (GGG 40.3 or ASTM A395)
- Connection Type
- Threaded connections; fluid connections available in BSP-BS21 or NPT, motive steam/exhaust connections available in BSP or NPT
- Connection Sizes
- Fluid inlet/outlet DN20 (3/4 in); motive inlet/exhaust outlet DN15 (1/2 in)
- Minimum Installation Height
- 0.2 m (from the pump base); recommended minimum installation height 0.3 m
- Pump Displacement per Cycle
- 2.6 L
- Maximum Condensate Capacity
- 830 kg/h (at a 1.0 m installation height, 4.5 barg motive pressure, and 2.5 barg total backpressure)
- Maximum Water Pumping Capacity
- 650 kg/h (at a 1.0 m installation height, 4.5 barg motive pressure, and 2.5 barg total backpressure)
- Pressure Equipment Compliance
- European Pressure Equipment Directive 97/23/EC
- Explosion Protection Compliance
- ATEX Directive 94/9/EC
- Casing Design Standard
- A.D. Merkblatter/ASME VIII
- Material Certificate
- EN10204 3.1.B certificate available
Application scenarios
Condensate Drainage from Steam Heat Transfer Equipment under Low Differential Pressure or Vacuum Conditions
Used at the condensate outlet of steam heat exchangers and other heating equipment. When load variations cause insufficient outlet differential pressure, return-line backpressure, or vacuum conditions, the equipment automatically drains condensate or pumps it using steam power according to the pipeline pressure conditions.
Condensate Drainage from Vacuum Heating Equipment with a Low Installation Height
Used for condensate drainage from heating equipment or process systems where installation space is limited and vacuum conditions may occur. The equipment can remove condensate under vacuum conditions, with a minimum installation height of 0.2 m and a recommended minimum installation height of 0.3 m.
Selection points
Steam-Powered Automatic Condensate Drainage and Water Pumping
Provides automatic condensate drainage or water pumping, using steam power without requiring electricity.
Stainless Steel Internal Moving Parts
Internal components including the float, pump valve linkage, springs, and inlet check valve seat are made of stainless steel.
Low Installation Height Requirement
The minimum installation height measured from the pump base is 0.2 m, with a recommended minimum installation height of 0.3 m.
DN20 Threaded Fluid Connections
The fluid inlet and outlet are DN20 threaded connections, while the motive steam inlet and exhaust outlet are DN15 threaded connections, available in BSP or NPT configurations.
Displacement per Cycle and Rated-Condition Capacity
Pump displacement per cycle is 2.6 L. At a 1.0 m installation height, 4.5 bar g motive pressure, and 2.5 bar g total backpressure, the maximum condensate capacity is 830 kg/h and the maximum water pumping capacity is 650 kg/h.
Installation & maintenance notes
Drainage and Filtration of the Motive Steam Line
The motive steam supply line must be properly drained and fitted with a 100-mesh strainer to prevent condensate and contaminants from entering the pump and causing valves or mechanisms to seize.
Correct Connection and Clear Passage of the Exhaust Balance Line
The DN15 exhaust balance line must be connected to the condensate outlet side of the equipment being drained and kept clear to prevent interrupted drainage or equipment flooding caused by inadequate venting and filling of the pump body.
Compliance with the Minimum Installation Height
The installation height measured from the pump base must be at least 0.2 m, with a recommended minimum of 0.3 m. Insufficient installation height will reduce the pump's filling and drainage capacity.
Tightening the Pump Cover Bolts in the Specified Sequence and to the Specified Torque
When reinstalling the pump cover after maintenance, tighten the bolts progressively in a diagonal sequence. The final tightening torque is 63+/-5 N m to prevent inadequate pump cover sealing and fluid leakage.
FAQ
How does the APT10-4.5 automatic condensate pump work?
The Spirax Sarco APT10-4.5 automatic condensate pump uses steam as its power source and combines pump and steam trap mechanisms to drain and pump condensate. The unit automatically drains or pumps water according to the pipeline operating conditions, requires no electrical power, and can remove condensate from heating equipment and process systems.
Which parameters need to be confirmed when selecting the APT10-4.5 automatic condensate pump?
Selection requires confirmation of the installation height, motive steam pressure, total backpressure in the condensate recovery system, heat exchanger operating pressure, maximum steam load, and temperature range of the heated medium. Correct selection requires the total backpressure to be lower than the motive pressure to meet the rated capacity requirements of the equipment.
What are the main connection specifications and pressure limits of the APT10-4.5?
The standard specification of the APT10-4.5 is DN20 × DN20. The inlet and fluid outlet connections are DN20 (3/4 in), while the motive inlet/exhaust outlet is DN15 (1/2 in). BSP or NPT threaded connections are available. The pump body design pressure is PN10, the maximum motive pressure and maximum operating pressure are 4.5 bar g, and the maximum backpressure is 4.0 bar g.
What operating conditions is the APT10-4.5 suitable for?
The APT10-4.5 is suitable for steam systems requiring automatic condensate removal or condensate lifting and transfer. It can be used for condensate handling in heating equipment and process systems. The product can operate under special pipeline conditions such as vacuum conditions. Specific applications must be confirmed based on the system pressure, backpressure, and installation conditions.
What should be noted when maintaining the APT10-4.5 automatic condensate pump?
The APT10-4.5 uses an integrated pump, steam trap, and check valve mechanism design without external seals or packing. During maintenance, corresponding components can be replaced according to the spare parts list, such as the pump cover gasket, inlet check valve, float, steam trap, and outlet check valve mechanism. Specific repair procedures should follow the Installation and Maintenance Guide supplied with the product.