Mini Bellows Metering Pumps
Mini Bellows Metering Pumps are ideal for low flow, low pressure metering applications. The pump is constructed entirely of plastic and uses GRI’s time-proven bellows technology to provide an accurate chemically-resistant metering pump with a long life, at an economical price.
Mini Bellows Metering Pump Operation:
The Mini Bellows Metering Pumps operate on a positive displacement principle. The rotation of the motor shaft is transmitted into an up and down linear motion through an adjustable concentric crank mechanism. This motion provides a continuous compressing and relaxing force on the bellows module, forcing fluid between two check valves located in the module’s valve body. Up to two separate bellows modules can be operated by single motor for proportioning up to four separate fluid mediums. The flow rate of each module is independently adjustable. Multiple bellows modules operate out-of-phase with each other for most efficient power usage.
Optimum Operating Conditions:
Optimum operating conditions consist of a 6” minimum suction life 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. For conditions where a positive suction head condition exists, an anti-siphon spring or anti-siphon spring kit can be added to aid the poppet valve seal properly during operation. See Accessories PDF file located in the Product Resources section located above right.
Bellow Metering Pump Flow Rates:
The flow rate of each bellows module is regulated by three factors:
- Diameter of the bellows,
- Speed of the gearmotor,
- Adjustment of the module stroke length.
Bellow Metering Pump Flow Adjustment:
The ½” and ¾” bellows modules can be adjusted to 20% of maximum stroke length, while 1”, 1-1/2” and 2” bellows modules can be adjusted down to 10% of maximum stroke.
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.
Mini Bellows Metering Pump Specifications:
Average Repeatability — From stroke-to-stroke ± 0.75%
Flow Rates — Range to 270 ml/min, Tandem models range to 432 ml/min
Max Fluid Temperatures — To 140°F (60°C)
Max Discharge Pressure — To 6 psi
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.
Note: All testing is done with water at an ambient temperature of 80 degree F. If specific gravity or viscosity of fluid being pumped is significantly greater than water (1.0), please consult factory.
The standard motor available for the Mini Bellows Pump is an AC voltage synchronous motor. Motors are UL recognized and continuous duty rated and are available in 115V, 50/60 Hz or 230V, 50/60 Hz.
Materials in Contact with Solution:
Connectors — Polypropylene
O-Rings (Elastomers) — EPT/EPDM or Viton®/Fluoroelastomer
Poppet/Duckbill Valves — EPT/EPDM or Viton®/Fluoroelastomer
Bellows — Standard Polypropylene Materials
Additional materials available, refer to OEM Section for details.
Mini Bellows Metering Pump Selection:
The pump selection procedure is detailed in the Mini Bellows Metering Pump Selection Guide or the Tandem Mini Bellows Pumps Selection Guide link or by navigating to any of the MBMP Series pumps listed below.
|•||Average repeatability from stroke-to-stroke, ±0.75%||•||Dry run capability||•||Self-priming||•||No dynamic seals||•||Superior corrosion resistance||•||Economical||•||Simple flow adjustment|
|Performance by Product Series|
Click above image or series link to customize a single bellow pump configuration.
Click above image or series link to customize a 2-tandem bellows pump configuration.
Poppet Valves and O-Rings
The standard elastomers for the poppet valves and O-rings are EPT/EPDM and Viton®/Fluoroelastomer. These elastomers have historically been able to handle the vast majority of the applications in which we’ve been involved. However, Butyl, Hydrin, Kel-F®, Silicone and Nitrile can be supplied for chemicals requiring such materials.
Duckbill Valves and O-Rings
Duckbill valves are required in those applications where heavy slurries or fibrous materials are being pumped. Heavy slurries should be flushed from the bellows before pump is shut down. Duckbill valves are available in the same elastomers as the poppet valves.
180 Hines Avenue • Bellville, Ohio 44813 • Tel: 419-886-3001 • Fax: 419-886-2338