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Engineered To Meet the Most Exacting Specifications... Yours.

GRI has been advancing the development of fluid pumping solutions for over half a century. Along the way, we’ve developed an extensive product line of cutting-edge pumping solutions for a wide array of industries and applications. But that truly is just the beginning.

Built with advanced materials, motors and methods, our high-quality, innovative pump lines are simply the perfect platform from which we create customized solutions. As your pump partners, GRI works in close collaboration with you and your team, evaluating your application and creating tailor-made, turnkey solutions built specifically to meet your specialized needs and requirements.

Our Begin Your Build engine enables you to get a jump on the process, helping us to quickly identify the appropriate category and product family from which we can begin to craft your perfect pump.

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Your Pumping Solutions.

Begin Your Build is a starting point to a solution specific to your application. The page results may not reflect all of your OEM variables. Please contact GRI to begin the discussion of your solution in more detail.

Compact Bellows Metering Pumps

Product Overview

Gorman-Rupp Industries’ line of Compact Bellows Metering Pumps were specifically designed for metering applications requiring low discharge pressures. Compact Bellows utilize GRI’s proven proprietary blend of polypropylene materials to provide an accurate and economical, long-lasting metering pump. A wide selection of valve and O-Ring elastomers produce chemical resistance pumps capable of handling both corrosive and non-corrosive fluids.

The Compact 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 four 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.

Any combination of ½”, ¾”, 1″, 1-1/2″ and 2″ bellows may be used in a pump. However, the total output must be limited to a maximum flow rate of 3000 ml/min.

For a complete description of our Compact Bellows Metering Pumps, including performance, options, replacement kits, and dimensional drawings, please click the blue "Pump Overview & Data Sheet" button.

Contact Us to Customize

Product Details

Applications include, but are not limited to:

  • 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
  • Wastewater and water treatment systems

Flow Rates: Range from 3.8 ml/min to 1620 ml/min, Tandem flow rates to 3,000 ml/min.
Max. Discharge Pressures: 5 psi
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.

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, contact GRI.

  • Repeatability from stroke-to-stroke to ± 0.5%
  • Self-priming
  • Corrosion resistant
  • Long life
  • Dry run capability
  • No dynamic seals
  • Maintenance free operation
  • Simple flow adjustment
  • Multiple OEM options

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 section located in the Product Overview Sheet.

Catalog gearmotors are available in 115V, 50/60 Hz or 220V, 50/60 Hz. Standard motor speeds are 45.6 and 90 RPM at 60 Hz and 38 and 75 RPM at 50 Hz. Motors are UL recognized 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.