Diaphragm Dosing Heads

Diaphragm dosing heads: a unique experience   

DKM – Clextral, the inventor of the intermediate fluid pump, designs and manufactures as standard hydraulic double diaphragm pumps.

The objectives: complete tightness, safety, total protection

Why choose DKM – Clextral hydraulic double diaphragm pumps?

  • Variety: when the pumped products or the conditions of use are difficult or hazardous, experience counts.

To deal with these problems,  DKM – Clextral uses a wide variety of purpose-oriented materials for both the pumping chamber and the diaphragms. Combining the advantages of the positive displacement pump and complete tightness, the hydraulic diaphragm pump is the best solution for numerous pumping requirements, especially where the pumped products or the conditions of use are difficult or hazardous. A wide range of materials is available for both the pumping chamber and the diaphragms.

  • Safety: since safety and reliability are essential considerations in industry,  DKM – Clextral designs and manufactures as standard equipment hydraulic double diaphragm pumps, with intermediate fluid.

The initial patent for the intermediate fluid pump is a  DKM – Clextral patent No. 1441747.

This principle offers two major advantages:

    • There is a double barrier between the pumped fluid and the oil. The intermediate fluid will be chosen for compatibility with the pumped fluid.
    • There process-side diaphragm is always clear; its travel is controlled by the rear diaphragm, which in turn is controlled at the front by the contour plate. The front diaphragm never comes into contact with the front of the dosing head. This is the essential solution for products that are abrasive or which contain particles, as the process-side diaphragm will never impede their travel.

To prevent any possibility of overpressure, the diaphragm dosing heads are fitted with a safety valves; this is factory calibrated -set or adjustable on site. In the event of a problem downstream from the delivery circuit, a quantity of oil equal to the displacement escapes through this valve. The automatic bleed, which is standard for large pistons, works independently of the safety valve so as to separate tasks and optimise maintenance costs.

A Major  DKM – Clextral Innovation:   

Controlled Diaphragm Automatic Compensation (CAMP)

The CAMP system, which is automatic and accurate, reduces the risks of diaphragm deformation and extends the life of the process diaphragms.  DKM – Clextral was the first manufacturer to originate and develop this principle (original patent No. 2164025).

How the CAMP system works:   

The volume of diaphragm control fluid must remain absolutely constant to ensure flow accuracy and reliability. The automatic, accurate CAMP system balances the flow of hydraulic between the high pressure side and low pressure side.

When oil has been lost, when the piston travels backward, the diaphragm pushes against the pilot P. Valve Sa1 opens and a volume of oil equal to the lost oil compensates internal loss by creating a vacuum through valve Sa2. In the event of depression in the suction circuit, valve Sa1 remains closed under the action of the spring R, and thus there is no intake through valve Sa2: the pump can cavitate without any damaging effect. Valves Sa1 and Sa2 are separated to facilitate maintenance operations.

The risks of diaphragm deformation are reduced to a minimum, further extending the life of the process diaphragms.

Diaphragm Rupture Detection: Total Protection   

Two types of diaphragm rupture detector are available on all the industrial pumps:

  • The sandwich diaphragm, compliant with standard APl 675. This technology was first patented by  DKM – Clextral (patent No. 264024) in 1971.
  • The resistivity probe: electronic diaphragm rupture detection.