Standard Bellows Metering

Product Overview

Bellows metering pumps operate on a positive displacement principle. Pumps are designed to displace both corrosive and noncorrosive fluids. Accurate to ± 0.5% from stroke to stroke, when pump is set 50% to 100% of full stroke. Discharge pressure is maintained over the entire flow range of the pump. Poppet valves are used to prevent backflow; and springs are available to provide a positive shutoff, preventing siphoning through the pump in applications where a positive suction head exists.

Typical applications include film and x-ray processors, silver recovery systems, wafer and silicon chip washers and processors, detergent dispensers, blood analyzing equipment, industrial floor scrubbers, thermo therapy equipment, waste removal systems, and wastewater and water treatment systems.

Specifications

Flow Rates: Range from 3.9 ml/min to 3000 ml/min, depending on pump configuration, gearmotor speed and stroke length.


Max. Discharge Pressures: Range from 5 to 50 psi depending on bellows size.


Max. Fluid Temperature: To 140°F (60°C).

Note: Reduce pressure rating by 50% for fluid temperatures over 120°F (49°C).


Viscosity/Slurries: Maximum fluid viscosity is 5,000 centistokes. Poppet valves can handle fine slurries. Duckbill valves are recommended for heavy slurries or fibrous materials. Heavy slurries should be flushed from the pump before shutdown.
Materials

  • Connectors – Polypropylene.
  • O-Rings (Elastomers) – EPT/EPDM, Hypalon®, or Viton®/Fluoroelastomer.
  • Poppet/Duckbill Valves – EPT/EPDM, Hypalon®, or Viton®/Fluoroelastomer.
  • Bellows – Standard Polypropylene Materials.

Additional materials available, refer to OEM Section

Operation

Bellows Metering Pump Operation
The Bellows Metering Pumps operate on a positive displacement principle. The rotation of the motor shaft is transmitted into an up and down motion through a lever pivot crank mechanism. This motion provides a continuous squeezing and relaxing force on a bellows module, forcing fluid in and out of the module. Discharge pressure is maintained over the entire flow range of the pump.

Optimum Operating Conditions
Optimum operating conditions consists of a 6″ minimum suction lift and a discharge head of not less than 6″. Pumps must be mounted vertically with the valve body at the top to obtain maximum metering accuracy.

Gearmotors

Gearmotors
Catalog gearmotors are available in 115V, 50/60 Hz or 240V, 50/60 Hz. Standard motor speeds are 39, 60, 90 and 165 RPM at 60 Hz. Motors are UL listed and continuous duty rated with a minimum life expectancy of 2000 hours. Perpetual running of motor is not recommended. If a non-stop application is encountered, the Gorman-Rupp Industries Heavy-Duty Bellows Metering Pump is recommended.

Selection Procedure

Pump Selection
Select a bellows size that meets your pressure requirements. Select a model with the bellows size that provides your required flow while operating closest to full stroke capacity. Best metering accuracy occurs when bellows modules operate at 50% or more of maximum output. For 24 hour continuous duty service, use one of the heavy-duty models.

Flow Rate and Discharge Pressure

The flow rate of each bellows module is regulated by three factors:

  1. Diameter of the bellows,
  2. Speed of the gearmotor, and
  3. Adjustment of the module stroke length.

Bellows are available in several different diameters. The full stroke displacement and discharge pressure of the pump is dependent on the size of the bellows as shown below:

Size 1/2" 1" 1-1/2" 2-1/2" STD 2-1/2" BOJ
Full Stroke Displacement in ml .5 5 10.5 55 27.5
Maximum Discharge Pressure (psi) 50 40 20 5 5

BOJ – BEL O JUST®; STD – Standard

Flow Adjustment

The flow rate of all bellows pumps can be adjusted by modifying the length of the discharge stroke. Adjustments can be made down to 10% of full stroke on all models except 1/2″ models which are limited to 20% of full stroke. Two styles of adjustment mechanisms are available.

Note: Best priming and metering accuracy occurs when the stroke length is 50% or greater.

Standard Crank – Adjustment cannot be made while pump is operating. An adjusting screw changes the stroke length of an eccentric crank.

BEL O JUST® Can be adjusted while the pump is operating. A knob regulates drive arm motion which modifies the stroke length of the bellows module.

Maximum Dry and Wet Priming Specifications in Feet (Meters)

Bellows Size Dry Prime 50% of Full Stroke Dry Prime 100% of Full Stroke Wet Prime 50% of Full Stroke Wet Prime 100% of Full Stroke
1/2″ 2.50 (.76) 8.67 (2.64) 5.83 (1.78) 17.17 (5.23)
1″ 3.08 (.94) 8.33 (2.54) 6.25 (1.91) 14.25 (4.34)
1-1/2″ 4.33 (1.32) 11.00 (3.35) 9.58 (2.92) 20.58 (6.27)
2-1/2″ 9.17 (2.80) 18.50 (5.64) 15.25 (4.65) 27.58 (8.41)

Select a Valve and O-ring

combination (X-Code) and tubing connectors (T-Code) for each bellows from the Parts Selection Guide found in the Product Overview Sheet. Specify duckbill valves if heavy slurries or fibrous materials are being pumped. Refer to the Chemical Resistance Section (under Product Resources) to help determine compatibility.

Model Specifications

Model Number Voltage Bellows Size Dia. Inches (No. of modules) Discharge Strokes per min (Motor RPM) 50Hz / 60Hz Max Flow mL/min per Module 50Hz Max Flow mL/min per Module 60Hz Max Discharge Pressure (PSI)
Single Bellows Standard
13960-022/024 115 or 230 1/2 (1) 32.5 / 39 16.3 19.5 50
13960-027/028 115 or 230 1/2 (1) 137 / 165 68.8 82.5 50
13300-007/008 115 or 230 1 (1) 32.5 / 39 162.5 195 40
13300-009/010 115 or 230 1 (1) 50 / 60 250.0 300.0 40
13300-045/046 115 or 230 1 (1) 75 / 90 375.0 450.0 40
13300-047/048 115 or 230 1 (1) 137 / 165 687.5 825.0 20
13325-001/002 115 or 230 1.5 (1) 32.5 / 39 341.3 409.5 20
13325-003/004 115 or 230 1.5 (1) 50 / 60 525.0 630.0 20
13325-005/006 115 or 230 1.5 (1) 75 / 90 787.0 945.0 20
13325-031/032 115 or 230 1.5 (1) 137 / 165 1443.8 1732.5 10
Single Bellows BEL O JUST
14280-006/007 115 or 230 1/2 (1) 32.5 / 39 16.3 19.5 50
14280-009/014 115 or 230 1/2 (1) 137 / 165 68.8 82.5 50
14250-005/006 115 or 230 1 (1) 32.5 / 39 162.5 195 40
14250-007/008 115 or 230 1 (1) 50 / 60 250.0 300.0 40
14250-014/015 115 or 230 1 (1) 75 / 90 375.0 450.0 40
14250-016/017 115 or 230 1 (1) 137 / 165 687.5 825.0 20
14251-001/002 115 or 230 1.5 (1) 32.5 / 39 341.3 409.5 20
14251-003/004 115 or 230 1.5 (1) 50 / 60 525.0 630.0 20
14251-005/006 115 or 230 1.5 (1) 75 / 90 787.0 945.0 20
14251-007/008 115 or 230 1.5 (1) 137 / 165 1443.8 1732.5 10
Two Tandem Bellows Standard
13701-021/022 115 or 230 1 (2) 50 / 60 250.0 300.0 20
13701-019/020 115 or 230 1 (2) 75 / 90 375.0 450.0 20
13726-016/017 115 or 230 1.5 (2) 50 / 60 525.0 630.0 10
13726-014/015 115 or 230 1.5 (2) 75 / 90 787.5 945.0 10
Two Tandem Bellows BEL O JUST
14324-029/030 115 or 230 1 (2) 50 / 60 250.0 300.0 20
14324-027/028 115 or 230 1 (2) 75 / 90 375.0 450.0 20
15904-003/004 115 or 230 1.5 (2) 50 / 60 525.0 630.0 10
15904-001/002 115 or 230 1.5 (2) 75 / 90 787.5 945.0 10
Three Tandem Bellows Standard
13700-011/012 115 or 230 1 (3) 50 / 60 250.0 300.0 20
13700-009/010 115 or 230 1 (3) 75 / 90 375.0 450.0 20
13716-012/13716/013 115 or 230 1.5 (3) 50 / 60 525.0 630.0 10
13716-009/010 115 or 230 1.5 (3) 75 / 90 787.5 945.0 10
Three Tandem Bellows BEL O JUST
14252-007/008 115 or 230 1 (3) 50 / 60 250.0 300.0 20
14252-005/006 115 or 230 1 (3) 75 / 90 375.0 450.0 20
15905-003/004 115 or 230 1.5 (3) 50 / 60 525.0 630.0 10
15905-001/002 115 or 230 1.5 (3) 75 / 90 787.5 945.0 10
Single Stroke Bellows
15090-001/002 120 or 240 1 (1) 8.3 / 10 41.5 50.0 40
15090-003/004 120 or 240 1.5 (1) 8.3 / 10 87.15 105.0 20
12800-007/026 120 or 240 2.5 (1) 8.3 / 10 456.5 550.0 5
Heavy Duty Bellows
15955-001/002 115 or 230 1.5 (1) 83 / 100 872.0 1050.0 20
15956-001/002 115 or 230 2.5 (1) 42 / 50 2310.0 2750.0 5
Dial-A-Flow
15950-001 115 1.5 (1) 50 / 60 525.0 630.0 20