Armstrong PT-516 High Capacity Pump Trap is the low maintenance, non-electric solution to moving large amounts of condensate and other liquids from low points, low pressures, or vacuum spaces to an area of higher elevation or pressure. Condensate can be returned at temperatures well above the 200°F (93°C) limit of conventional electric pumps without the headaches of leaking seals or cavitation. Effective recovery and return of hot condensate are essential to overall plant efficiency while conserving energy.

Features

• Economical non-electric operation: Uses inexpensive steam, air, or inert gas.
• Low-maintenance operation: No leaking seals, impeller, or motor problems means lower maintenance. No NPSH issues.
• Lower installation costs: Single trade required for installation and maintenance.
• Peace of mind: Standard unit is intrinsically safe—explosion-proof.
• Durable construction: ASME code-stamped carbon steel body vessel.
• Corrosion resistance: Internals are all stainless steel for corrosion resistance and long life.
• Heavy-duty springs: Springs are made from long-lasting Inconel X-750.
• Efficiency: A closed loop means no motive or flash steam is lost. All valuable Btu’s are captured and returned to the system.
• Safety: The pump can be used in flooded pits without fear of electrocution or circuit breaker defaults.
• Externally removable/replaceable seats: Seats can be replaced or cleaned without removing the mechanism assembly.

Typical Applications

• Low pressure heating systems
• Process heat exchanger or coils with modulating steam control
• Remote installations (tracing, tank farms or remote coils)
• Systems under vacuum
• Hazardous (explosion proof) areas
• Caustic environments
• Sumps or submersed areas

Materials of Construction

Name of Part	Description
Cap, Body, Bolting	Fabricated steel 150 psi ASME Sec. VIII design “U” stamp coded
Cap Gasket	Stainless steel spiral wound
Inlet Valve Assembly	Stainless steel
Vent Valve Assembly	Stainless steel
Mechanism Assembly: Frame, Float and Spring	Stainless steel (Inconel X-750 springs)

Pump Trap Operation

1. At start up, the float lies at its lowest position in the bottom of the tank. The motive inlet valve is closed and the vent valve is open.
2. Liquid enters the pump body by gravity through the inlet check valve. Back pressure (typically) holds the discharge check valve closed. The float becomes buoyant and begins rising.
3. Continued rising of the float, through linkage, increases spring compression until it reaches its upper tripping point. The linkage then snaps upward over center. This upward motion opens the inlet valve and closes the vent valve simultaneously.
4. Steam, air or gas enters the inlet valve and builds pressure inside the pumping trap. This pressure will close the inlet check valve and force liquid out through the discharge check valve as it opens.
5. The discharge cycle will lower the float level until it reaches its lower tripping point. The compression spring will cause the mechanism to snap over its center point downward. This action will close the motive inlet valve and simultaneously open the vent valve.
6. Venting of pressure from the body opens the inlet check valve and closes the discharge check valve. Liquid now flows by gravity through the inlet check valve into the pumping trap body as a new cycle begins.

Sizing and Selection

Published capacities below are based on actual steam testing using a minimum 200°F condensate and the use of external check valves supplied by Armstrong.

Motive Pressure (psig)	Total Lift or Back Pressure (psig)	Steam Motive (lb/hr)	Air Motive (lb/hr)
15	5	28,962	57,619
35	5	42,563	64,738
75	5	54,796	71,142
150	5	65,922	*
25	15	36,720	50,783
50	15	45,196	58,013
100	15	55,675	65,243
150	15	62,923	*
35	25	29,212	46,238
75	25	38,548	56,313
100	25	42,454	60,141
50	40	26,210	41,244
100	40	30,555	51,828
150	40	33,097	*
70	60	25,973	32,026
100	60	28,042	40,951
150	60	30,394	*
100	80	23,892	34,893
150	80	24,570	*

*(Note: Capacities shown are for 4" x 4" connections with a 24" fill head. Consult factory for values marked with )

Installation Guidelines

Motive Pressure Recommendation

Although the maximum operating pressure is 150 psig (10.34 bar), it is recommended that the motive pressure be set to 30 psig (2.07 bar) above the back pressure. This will provide optimum performance and reduce venting time between cycles.

Filling Head: Install the PT-516 below the equipment being drained. A minimum filling head of 24" is required for the PT-516. Filling head is measured from the bottom of the receiver or reservoir pipe to the top of the PT-516 cap.

Check Valves: The PT-516 will not function without inlet and discharge check valves. Connect the Armstrong supplied check valves to the pump. The PT-516 has two (2) 4" flanged connections. Best performance is achieved when a minimum of horizontal pipe is used before the inlet check valve.

Motive Inlet Piping: Connect the motive force piping (steam, air, or gas) to the inlet connection on the PT-516 cap. Proper piping and trapping of the motive supply line must include a strainer, check valve, properly sized drip leg with mud pocket and drip trap. The motive supply line must be a minimum of 2".

Vent Connection: Piping from the pump’s cap connection should be installed vertically upward when possible and unrestricted. The minimum size of this vent piping should be 2". If piping travels longer than 10 feet, the piping should be expanded to a minimum of 3".

Cycle Counter Installation: There is a 1/4" connection on top of the cap where the cycle counter can be mounted. One (1) 1/4" pigtail siphon and 1/4" isolation valve are required. It is very important that a steel siphon or “pig tail” be used prior to the cycle counter to avoid any damage to the cycle counter.

Packaged Connections: A pumping trap receiver package designates the number of pumps with an “S” for single (one pump), “D” for duplex (two pumps), “T” for triple (three pumps) and “Q” for quad (four pumps). For example: SPT-516RP or DPT-516RP. All receiver tanks should be operated at atmospheric pressure (vented) unless the package was ordered with an ASME coded tank.

Maintenance & Troubleshooting

Safety Warning

For Safety of Personnel - Vent line piping should be isolated from equipment and pump pressure should be relieved prior to breaking connections. WATER MAY RUN OUT OF THE VENT CONNECTION WHEN PIPING IS BROKEN. CARE SHOULD BE TAKEN TO AVOID DANGER TO PERSONNEL OR DAMAGE TO NEARBY EQUIPMENT.

1. Close the valves in the motive supply, vent, condensate and discharge lines. Make sure that the PT-516 is completely relieved of pressure before breaking any connections.
2. Remove cap assembly and inspect mechanism for freedom of movement. Remove any dirt or scale inhibiting the motion of the mechanism. (IMPORTANT NOTE: The PT-516 mechanism weighs approximately 120 lbs. You will need a forklift or overhead lift to remove the mechanism from the pump body. The withdrawal distance is approximately 18 inches.)
3. Check the float for pinhole leaks, dents or corrosion. Immerse in hot water and look for air bubbles to detect pinhole leaks.
4. Inspect motive and vent valves for wear. Reinstall or replace parts as necessary.
5. Replace gasket if damaged before reattaching the cap assembly to the pump body.
6. Inspect inlet and discharge check valves for freedom of movement. Ensure that both check valves seat properly.