The Armstrong PT-104 Mini Pump Trap is the smallest non-electric solution that can move condensate or other liquids from lower to higher points and from lower to higher pressures. Condensate can be returned at temperatures well above the 210°F limit of conventional electric centrifugal pumps without the headaches of leaking seals or cavitation problems. The PT-104 Mini Pump Trap is a small solution for a big problem, designed to fit in tight space requirements while allowing minimal fill head.

Features and Benefits

• Non-electric: Operates using inexpensive steam, air, or inert gas.
• Low maintenance: No leaking seals, impeller, or motor problems, reducing maintenance and downtime.
• Small and compact: Low profile body fits in tight space requirements while allowing minimal fill head.
• Reduced installation cost: Single trade required for installation and maintenance.
• Explosion proof: Standard unit is intrinsically safe.
• All stainless steel internals: Provide corrosion resistance and long service life.
• Durable spring: Long-lasting Inconel X-750 spring.

Specifications and Materials

Connection Sizes

Connection	Type	in	mm
Inlet	NPT	1	25
Outlet	NPT	1	25
Vent	NPT	1/2	15
Motive Pressure	NPT	1/2	15
Optional Gauge Glass	NPT	1	25
Optional Cycle Counter	NPT	1	25

List of Materials

Name of Part	Material
Body and Cap	Cast Iron ASTM A48 cl.30
Vent/Inlet Valves	Stainless Steel
Mechanism Assembly	Stainless Steel
Spring	Inconel X-750
Gasket	Compressed non-asbestos
Bolts	SA 449
Nuts	ASTM A194 Gr.2H
Plug	Cast Iron

Physical Data

Dimension	in	mm
A	12	305
B	18-1/2	470
C	13-1/2	343
D	10-3/4	272
F	5-1/2	140
G	1-5/16	33
H	12-1/2	317
U	1-1/4	32
V	3/8	9
T	10-1/16	256
Weight lb (kg)	169	(77)
Bronze Check Valves lb (kg)	4	(2)
Stainless Steel Check Valve lb (kg)	4	(2)
Maximum Operating Pressure	100 psig (7 bar)
Maximum Allowable Pressure	150 psig (10 bar) @ 450°F (232°C)

Note on Motive Pressure

Although the maximum operating pressure is 100 psi (7 bar), it is highly recommended that the motive be set only 15 - 20 psi (1.0 - 1.4 bar) above the discharge pressure. For applications with greater than 18" of filling head or condensate temperature less than 185°F, it is recommended that the motive pressure be set 25-35 psi above the backpressure. Air is the preferred motive for condensate temperatures less than 180°F (82°C).

Pumping Trap Operation

1. At start-up, the float lies at its lowest position in the bottom of the body. The motive inlet valve is closed and the vent valve is open.
2. Liquid enters the pump body by gravity through the inlet swing check valve. Back pressure (typically) holds the discharge stainless steel check valve closed. The float becomes buoyant and begins rising.
3. Continued rising of the float, through linkage, increases spring tension until the float reaches its upper tripping point. Energy is then released instantly from the springs, causing the linkage to snap upwards over center. This upward motion opens the motive inlet valve and closes the vent valve simultaneously.
4. Steam, air, or inert 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.
5. The discharge cycle will lower the float level and, through linkage, increase spring tension until the float reaches its lower tripping point. Energy is then released instantly from the springs, causing the linkage to snap over center downward. This downward motion closes the motive inlet valve and opens 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.

Installation Guidelines

Filling Head: Install the pumping trap below the equipment being drained. A recommended filling head of 6" (152 mm) is recommended for the Model PT-104. Filling head is the distance between the bottom of a vented receiver or reservoir pipe and the top of the pumping trap cap. Greater fill heads increase the capacity of the pump trap; however, it is not recommended to have a filling head greater than 24 inches.

Liquid Reservoir: Liquid flowing from the equipment being drained must be stored during the pump’s discharge cycle. A liquid reservoir (pipe reservoir) or vented receiver should be installed in a horizontal plane to prevent flooding of equipment.

Check Valves Required

The pumping trap will not function without inlet and discharge check valves. Connect the Armstrong supplied check valves to the pump. The swing check is the inlet check valve and the spring assisted valve is used at the pump discharge.

Motive Inlet Piping: Connect the motive force piping (steam, air or inert gas) to the inlet connection on the pump 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 (for steam motive). A pressure reducing valve must be used when the motive pressure exceeds 100 psi (7 bar).

Typical Hook-Ups

Vented System

Pumping of condensate from vented receiver handling single or multiple steam trap discharges. Motive force of steam is depicted.

Closed Loop Systems

Draining liquid from equipment under vacuum. The Pumping Trap provides drainage assistance whether liquid discharge is to gravity or overhead.