Pump Trap
IB-100-G
Pumping Trap
Installation and Maintenance
This bulletin should be used by experienced personnel as a guide to the installation and maintenance of the
pumping trap or pumping trap package. Selection or installation of equipment should always be accompanied by
competent technical assistance. We encourage you to contact Armstrong or your local representative if further
information is required.
The maximum operating pressure for all Armstrong model pumping traps is 125 psig (9 bar). The
maximum design pressure for PT-300/400 models is 150 psig at 650°F (10 bar @ 343°C). The
PT-200 Series pumping traps weigh 210 lb (96 kg), PT-300 Series weigh 150 lb (68 kg), PT-400 Series
weigh 166 lb(75 kg) and the PT-3500 Series weigh 270 lb (123 kg).
Figure 1
PT-200 Series
Cast Iron Body
Figure 2
PT-300 Series
Horizontal Steel
Body, ASME Coded
Figure 3
PT-400 Series
Vertical Steel
Body, ASME Coded
Figure 4
PT-3500 Series
Cast Iron Body
Note: Although the maximum operating pressure is 125 psi (8.5 bar), it is highly recommended that
the motive be set only 15 - 20 psi (1.0 - 1.4 bar) above the discharge pressure. This will provide
optimum performance and reduce venting time between cycles.
Pumping 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 swing 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 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. See figure 4 on page 2.
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 as it
opens.
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.
Pumping Trap
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.
Figure 4
Hex Nut
Spring Arm
Spring End
Mechanism Support
Retrofit
Pin Pivot
Valve Actuator
Valve Actuator Rod
Float Arm
Spacer
Pivot
Pin Pivot
Pin Pivot
Inconel Spring
Retaining Ring
Bolt
Hex Nut Jam
Suggested Installation of Accessories
The gauge glass assembly will have male NPT connections.
If mounting on a PT-200 Series pumping trap, one (1) 1/2" x close nipple and
one (1) 1/2" coupling will be required. The PT-300 series and PT-400 Series
pumping traps will not require any additional parts.
Cycle Counter:
If a cycle counter is required the installation will be the same for all model
pumping traps. There is a 1/2" connection on the cap of the pumping traps
where the cycle counter may be mounted. 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. See figure 5.
Figure 5
Installation
Note: On pre-piped packaged units, inspect and tighten all threaded fittings (such as unions,
etc.) which may have loosened during shipment.
Filling Head:
Install the pumping trap below the equipment being drained. A minimum filling head of 6" (152 mm)
is recommended for Models PT-204 and PT-206 and 12" (304 mm) for all models in the PT-300,
PT-400 and PT-3500 series. Filling head is the distance between the bottom of a receiver or
reservoir pipe and the top of the pumping trap cap. See typical hook-up on page 7 for an example.
All inlet fittings must be fully ported and match the pump's liquid inlet connection size. Greater fill
heads increase the capacity of the pump trap. Reference capacity chart for multiplying factors for
other filling heads in Catalog 326.
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. Please contact your local Armstrong representative for
2
Pumping Trap
questions regarding reservoir pipe sizing or reference reservoir sizing data in catalog 326,
page 199.
Check Valves:
NOTE: 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, a stainless
steel in-line spring type check valve is used at the pump discharge. The use of Armstrong
supplied check valves is necessary to ensure the pump will attain published capacities.
Stainless steel in-line spring type check valves are recommended for applications where the
differential pressure between the motive pressure and back pressure is greater than 25 psi. The
stainless steel check valves are also a good choice for critical applications where the extended life
of the stainless steel check valve would be of great value.
The following guidelines apply if the Pumping Trap is installed without Armstrong supplied check
valves.
-- Inlet check valves should be bronze swing type with teflon disc, Class 150 (minimum). Pipe size of the check valve must match the size of the pump's liquid inlet connection.
-- Discharge check valve should be in-line spring assist type, Class 150 (minimum) and match the
size of the pump's liquid discharge connection.
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. The drip trap discharge line should be connected
to the reservoir piping or vented receiver when practical. See figure 5 and 6 on page 7. It is
recommended to install a union near the motive inlet (valve seat) to provide quick access to the
externally removable seat.
Note: To visually determine the location of the motive connection, for Series PT-200, PT-300, and
PT-3500, look into the pumping trap's condensate inlet and the motive connection will be on the
right side of the cap and is 1/2" NPT.
Note: For Series PT-400, the motive connection will be the 1/2" NPT connection in the cap that is
not steel plugged.
Maximum operating pressures for the pump trap 125 psi (9 bar). A pressure reducing valve
must be used when the motive pressure exceeds 125 psi (9 bar). It is also recommended that
motive pressure be set between 15-20 psi (1.0 - 1.4 bar) above the total discharge pressure (total
discharge pressure = vertical lift in psi plus return line pressure). This pressure setting keeps
venting time to a minimum and, when using steam, reduces the temperature differential. The PRV
should be installed as far from the pump trap as possible. A good rule is to use a minimum of 10 ft.
of 1" pipe after PRV.
Installation of a safety relief valve and pressure gauge is recommended in the motive force supply
line. The relief valve should be set for 150 psig (10 bar).
3
Pumping Trap
Vent Connection ("Open System" - vented to atmosphere):
Piping from the pump's cap connection labeled "Vent" should be installed vertically upward when
possible and unrestricted. If piping travels greater than three feet, the piping should be expanded to
one inch or greater. If a horizontal run is required, this line should be pitched toward the pump trap in
order to be self draining. It is recommended to install a union near the vent connection (valve seat) to
provide quick access to the externally removable seat.
Note: To visually determine the location of the vent connection for Series PT-200, PT-300 and
PT-3500, look into the pumping trap's condensate inlet and the vent connection will be on the left side
of the cap and is 1" for PT-300/3500.
Note: The location of the vent connection for Series PT-400 is the 1" NPT connection in the cap.
Vent Connection (Closed loop system):
From the pump cap connection labeled "Vent", the equalizing line should be routed to the top of the
equipment being drained or it's outlet piping immediately after the heat exchange equipment. An
Armstrong thermostatic air vent is recommended (for steam) at the high point of the exhaust line. (See
Figure 7 on page 8.) Piping of the equalizing line should be a minimum 1" (25 mm) diameter and must
be pitched in order to be self draining.
If pressure from the equipment being drained could ever exceed back pressure against the pump, a
properly sized inverted bucket steam trap with a large vent or a float and thermostatic trap must be
installed between the pump and discharge check valve. See Figure 9 on page 8.
Packaged Receiver Vent Connections: The receiver vent must be unrestricted and atmospherically
vented unless an ASME coded tank is specified.
Packaged Pump Trap Vent Connections: Piping from the pump's cap connection labeled "vent"
should be installed upward to connect with the receiver vent line, and be a minimum of one (1) inch (25
mm) diameter.
Package Connections:
NOTE: All receiver tanks should be operated at atmospheric pressure (vented) unless the package
was ordered with an ASME coded tank.
A pumping trap receiver package designates the number of pumps with a "S" for single (one pump), "D"
for duplex (two pump), "T" for triple (three pump), and "Q" for quad (four pumps). For example: SPT308RP or TPT-412RP. The "LBRP" at the end of the model number means low boy receiver package.
All Armstrong model pumping traps have 1/2" (10 mm) NPT gauge glass connections.
NOTE: Replace any temporary plastic plugs in these connections with permanent steel plugs or
appropriate fittings before start-up.
4
Pumping Trap
Start-Up
1. Slowly open motive force (steam, air or inert gas) supply to Pumping Trap providing pressure to the
inlet valve. Check for proper operation of drip trap on the motive line if using steam.
2. Open isolation valves leading to pump liquid inlet and discharge lines.
3. Open any additional valves upstream allowing liquid to enter Pumping Trap from the equipment
being drained. Pump will begin discharging when body is nearly full.
4. Proper operation includes an audible exhaust after each pump cycle. If operation doesn't seem
proper, recheck the installation and start-up procedure. Contact Armstrong or your local Armstrong
Representative if necessary.
5. Armstrong strongly recommends the use of overflow piping on receiver tanks in open condensate
return systems. Properly installed overflow piping increases the efficiency of the system, while
addressing potential safety issues involved with the unintentional escape of hot condensate.
One suggestion would be the use of a "P"-trap to form a sufficient water seal. Be sure to check
that a water seal has formed to prevent venting of steam through the overflow connection during
operation.
Maintenance
1. Close the valves in the motive supply, vent, condensate supply and discharge lines. Also close the
shut-off valve to the receiver for packaged units. Make sure that the pumping trap is completely
relieved of pressure before breaking any connections.
NOTE: If a problem is suspected with motive or vent valve and seat combinations, the pump
cap may not need to be removed. The seats are externally replaceable. This provides for
visual inspection and cleaning of the seats without removal of the cap.
2. Break motive inlet and vent (all cap) connections. Remove bolts and lift the cap. A 15 inch (381
mm) withdrawal distance is required in order to remove the mechanism assembly with float for all
Armstrong Pumping Traps.
NOTE: Mechanism assembly is factory set. No adjustment to mechanism assembly should
be made.
3. Inspect the mechanism for freedom of movement. Remove any dirt or scale inhibiting the motion of
the mechanism. See Figure 4 on page 2.
4. Check condition of the springs. If defective, remove retaining rings and slide springs (with spring
ends) from pins. Replace springs (with spring ends) and install new retaining rings. Once the
retaining rings have been removed they should not be reused.
5. Check the float for pinhole leaks, dents, or corrosion. Immerse in hot water and look for air bubbles
to detect pinhole leaks.
5
Pumping Trap
6. Inspect seating surfaces of motive inlet and vent valves for evidence of wear. Clean the surfaces.
Each valve slides out from its position in the valve actuator. Reinstall or replace parts as necessary.
Removal of the inlet or vent seat may require replacement of the appropriate metal gasket before
either seat is reinstalled or replaced. The same number of gaskets should be put back as were
removed.
7. Inspect inlet check valve and discharge check valve for free movement. It is important that both
check valves are able to fully seat. Foreign material or debris may damage seating surfaces.
Typical Hook-Ups
NOTE: Hook-up sketches depict the Pumping Trap for clarity. However, the cap inlet and vent
connections are actually located closer to each other than shown.
Vented Systems
Return Line
Steam Supply
Vent
Steam
Coil
Steam
Trap
Strainer
Lift
1” Equalizing Line
Strainer
Vented Receiver
FIGURE 5:
Condensate drainage to vented receiver
with overhead condensate return. Use of
the Pumping Trap, combined with proper
sizing of the steam trap and receiver assures
successful coil drainage under low pressure
conditions.
Inlet
Filling Head
Vent
Steam
Trap
Check
Valve
Check
Valve
Pumping
Trap
Return Line
Vent
Steam Supply
Heat
Exchanger
Heat
Exchanger
1” Equalizing Line
Steam Trap
Strainer
Steam Trap
Vented
Receiver
Multiple Trap
Discharges
Lift
Inlet
Filling Head
Vent
Steam
Trap
Check
Valve
Check
Valve
Pumping
Trap
6
FIGURE 6:
Pumping of condensate from vented receiver
handling multiple steam trap discharges.
Motive force of steam is depicted.
Closed Loop Systems
A closed loop system must be installed with caution and if any questions arise, contact Armstrong Fluid
Handling's Application Engineering Department.
Return Line
Steam Supply
Steam Supply
Air Vent
Steam Coil or
Heat Exchanger
Air Vent
Strainer
Vacuum Breaker
Lift
FIGURE 7:
Draining steam coil or heat
exchanger when pressure in heat exchanger
is lower than return line pressure combined
with overhead lift. Please note the equipment
is not trapped. In this application the pumping
trap is used as both a steam trap and a pump.
1” Equalizing Line
Vented Receiver
Inlet
Filling Head
Vent
Steam
Trap
Check
Valve
Check
Valve
Pumping
Trap
Return Line
Steam, Air or
Gas Supply
1” Equalizing Line
Vacuum
Space
Lift
Strainer
Filling
Head
installation.
FIGURE 8:
Draining liquid from equipment under vacuum.
The Pumping Trap provides drainage
assistance whether liquid discharge is to
gravity or overhead.
Steam
Trap
Inlet
Vent
Check
Valve
To Drain
Check
Valve
Pumping
Trap
Return Line
Steam Supply
Steam Supply
Air
Vent
Heat Exchanger
Air
Vent
Vacuum Breaker
Strainer
Lift
1” Equalizing Line
Reservoir Piping
Inlet
Filling Head
Vent
Steam
Trap
Check
Valve
Check
Steam Valve
Trap
Pumping
Trap
7
FIGURE 9:
Drainage from a heat exchanger in a closedloop system where the supply pressure may
be higher or lower than the back pressure.
If the heat exchanger pressure exceeds
the back pressure the pumping trap will
be idle and the steam trap will prevent the
steam from "blowing through" into the return
line. Motive force of steam is depicted.
NOTE: It is suggested that Armstrong
Fluid Handling's Application Engineering
Department be contacted prior to
Troubleshooting Flow Charts
For Safety of Personnel - Vent line piping should be isolated from equipment and pump pressure
should be relieved prior to breaking connections. WARNING: 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. Pump Does Not Cycle During Start-Up
Is motive inlet supply closed?
Yes
No
Is the pumping trap filling with condensate?
Yes
Is condensate discharge line valved off?
No
Is motive pressure too low to
overcome back pressure?
No
Is pump airbound?
No
Open necessary valve(s).
Yes
Increase motive pressure to 15 psi
(1.0 bar) greater than back pressure.
Yes
Yes
Is pump vented to Yes
Make certain vent line atmosphere.
is unrestricted and
self draining.
No
For closed loop:
Isolate pump vent line from pressurized equipment and with personnel clear, break vent connection piping. If pump cycles, make sure line is self-
draining and consider a thermostatic air vent at
high point in vent line (if steam is used).
8
Troubleshooting Flow Charts -- Continued...
For Safety of Personnel - Vent line piping should be isolated from equipment and pump pressure should be
relieved prior to breaking connections. WARNING: 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.
2. Excessive flash steam passed through vent
Are defective steam traps discharging
into condensate inlet line?
Yes
Repair or replace traps.
Yes
Motive valve may be leaking.
No
Is reservoir piping or vented
receiver used before pump?
No
Add liquid reservoir.
3. Pump cycles but equipment or piping is flooded
Is pump undersized?
No
Does piping provide insufficient
filling head?
Yes
Isolate pump. Separate
pump vent from receiver
vent, turn off motive if
steam stops. Remove
externally replaceable
seat. Inspect for dirt.
Visually inspect valve
and seat. Replace if
worn. (Valve replacement
requires removal of Pump
cap.)
NOTE: See Catalog 326 for sizing.
Yes
Install additional pump.
Yes
Lower pump as necessary.
Yes
Increase motive pressure as required.
Yes
Verify pump rated capacity at actual
conditions and increase motive pressure
as required.
No
Is motive pressure insufficient for
pump to provide rated capacity?
No
Is back pressure greater than
anticipated?
No
Is condensate inlet line restricted?
Yes
Use full ported fittings, open all valves fully
and eliminate any blockages.
No
Is inlet check valve hanging open?
Isolate and inspect check valve and clean
or replace as required.
Yes
9
Troubleshooting Flow Charts -- Continued...
For Safety of Personnel - Vent line piping should be isolated from equipment and pump pressure should be
relieved prior to breaking connections. WARNING: 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.
4. Pump stops cycling and equipment is flooded
Is motive pressure insufficient?
Yes
Increase motive pressure to 15 psi
(1.0 bar) greater than back pressure.
No
Are motive pressure and static
back pressure at pump equal?
Yes
Check for a closed downstream valve
or line blockage.
Yes
Isolate and inspect check valve and
clean or replace as required.
Yes
Remove externally replaceable inlet
seat and inspect for dirt. Visually
inspect valve and seat. Replace if
worn. (Valve replacement requires
removal of Pump cap.)
Yes
Are springs broken?
No
Is discharge check valve stuck closed?
No
Isolate vent line from equipment being drained
and break piping at pump vent connection.
No
With condensate inlet and discharge lines closed
and motive pressure line slowly opened, does
leakage occur at vent connection?
No
Slowly open condensate inlet line and, with
motive pressure line open, observe vent
connection (keeping personnel clear). Does
liquid run out vent connection?
No
Contact local Armstrong
Representative
No
If mechanism cycled, open liquid discharge line.
Does pump work normally?
Yes
Vent line may be vapor locked.
Ensure it's self draining.
Yes
Open valve.
Yes
Isolate and inspect check valve and
clean or replace as required.
No
If mechanism does not cycle, is an
upstream valve closed?
No
Inlet check valve is stuck closed.
10
Yes
Replace
Required
Parts
Troubleshooting Flow Charts -- Continued...
For Safety of Personnel - Vent line piping should be isolated from equipment and pump pressure should be
relieved prior to breaking connections. WARNING: 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.
5. Chattering or knocking in return line after discharge
Piping design combined with
operation of pump creating
vacuum at pump outlet?
Yes
Install vacuum breaker at return line
high point.
No
Does condensate inlet pressure
equal or exceed static back
pressure?
Yes
Are failed steam traps increasing
condensate inlet pressure?
Yes
Repair or replace traps.
No
A steam trap is required after the
pump in closed loop modulating
systems. See Figure 9 on page 8.
6. Excessive chatter from inlet check valve
(For low liquid inlet)
Is check valve either supplied by
Armstrong or follow Armstrong
recommendations?
Yes
Is check valve worn?
No
No
Install proper check valve.
Yes
Repair or replace check valve as required.
Consider installation of a stainless
steel in-line check valve.
For additional information on Pumping Traps, contact your Armstrong Representative and request
Catalog No. 326.
11
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Limited Warranty and Remedy
Armstrong International, Inc. (“Armstrong”) warrants to the original user of those products supplied by it and used in the service and
in the manner for which they are intended, that such products shall be free from defects in material and workmanship for a period of
one (1) year from the date of installation, but not longer than 15 months from the date of shipment from the factory, [unless a Special
Warranty Period applies, as listed below]. This warranty does not extend to any product that has been subject to misuse, neglect or
alteration after shipment from the Armstrong factory. Except as may be expressly provided in a written agreement between Armstrong
and the user, which is signed by both parties, Armstrong DOES NOT MAKE ANY OTHER REPRESENTATIONS OR WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR ANY IMPLIED
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE.
The sole and exclusive remedy with respect to the above limited warranty or with respect to any other claim relating to the products
or to defects or any condition or use of the products supplied by Armstrong, however caused, and whether such claim is based upon
warranty, contract, negligence, strict liability, or any other basis or theory, is limited to Armstrong’s repair or replacement of the part
or product, excluding any labor or any other cost to remove or install said part or product, or at Armstrong’s option, to repayment of
the purchase price. As a condition of enforcing any rights or remedies relating to Armstrong products, notice of any warranty or other
claim relating to the products must be given in writing to Armstrong: (i) within 30 days of last day of the applicable warranty period,
or (ii) within 30 days of the date of the manifestation of the condition or occurrence giving rise to the claim, whichever is earlier. IN NO
EVENT SHALL ARMSTRONG BE LIABLE FOR SPECIAL, DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING,
BUT NOT LIMITED TO, LOSS OF USE OR PROFITS OR INTERRUPTION OF BUSINESS. The Limited Warranty and Remedy terms herein
apply notwithstanding any contrary terms in any purchase order or form submitted or issued by any user, purchaser, or third party and
all such contrary terms shall be deemed rejected by Armstrong.
15
Armstrong Steam and Condensate Group
816 Maple Street, Three Rivers, MI 49093 – USA Phone: (269) 273-1415 Fax: (269) 278-6555
armstronginternational.com
Designs, materials, weights and performance ratings are approximate
and subject to change without notice.
Visit www.armstronginternational.com for up-to-date information.
IB-100-G
Printed in U.S.A. - 9/09
© 2012 Armstrong International, Inc.
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