Multi-layer diaphragm pumps of type RF409.2-ML

Flow rate from 11 l/h to 220 l/h, counter pressure up to 20 bar

By using a multi-layer diaphragm, a safety technical demanding metering can be realized. Increased safety requirements are guaranteed by a secure diaphragm monitoring (pressure switch, pressure gauge, etc.).

Product documentation:
Product information Series 4 Multi-Layer Diaphragm Pumps

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Capability characteristics

  • Increased operational safety
  • Longer diaphragm lifetimes
  • Higher feed pressure
  • Leakage-free
  • Highest dosing accuracy
  • Dry run safety
  • Hight quality materials
  • Continuous operation with minimum maintenance
  • Long operating life
  • Easy to operate
  • Diaphragm rupture indication by manometer

Field of application

Flow free mediums with the following characteristics:

  • aggressive
  • viscous
  • radioactive
  • flammable
  • odorous
  • toxic


Design and Function

Multi-layer diaphragm technology

High operational safety via multi-layer diaphragm technology and integrated diaphragm monitoring.
Up to ten times higher lifetime of multi-layer diaphragms in comparison to single layer diaphragms.
Excellent priming characteristics without additional equipment.
Applicable to explosion-hazardous areas via optional equipment components.
Simple commissioning thanks to sera's "plug & dose".

The multi-layer diaphragm consists of three layers:

  •      working diaphragm
  •      signal diaphragm
  •      protective membrane

If the diaphragm is damaged, the multi-layer diaphragm technology guarantee zero leakage. The damage to the working diaphragm has no direct failure of the dosing pump. The pump can continue operating for a limited time.

Materials and options

The best suited material is available for each dosing medium!

  • Pump body and valves: PVC, PP, PVDF, 1.4571, 1.4581, Titanium, Hastelloy, PP-FRP, PVDF-FRP
  • Valve balls: PTFE, 1.4401, Hastelloy
  • Valve seals: EPDM, FPM, FEP-covered
  • Working diaphragm: PTFE (3-ply)

Please ask us for any material required but not mentioned here

Available designs

Typ Q (at 50 Hz) p/max.

up to 11 l/h

20 bar

RF409.2-17ML up to 17 l/h 20 bar
RF409.2-45ML up to 45 l/h 16 bar
RF409.2-110ML up to 110 l/h 10 bar
RF409.2-220ML up to 220 l/h 4 bar