Ideal for “trickle-feed” applications

The use of a liner with a Mucon Iris Diaphragm Valve installation may enhance the operation and capability of the valve typically by –

1. Acting as a hygienic and protective liner.
2. Assisting diaphragm opening.
3. Combating diaphragm wear.

Liners can be used on their own or with an adaptor.

1) Use As A Hygienic or Protective Liner
By inserting a liner through the diaphragm of the Mucon Iris Valve, you can isolate the valve components such as the body, clamp ring and diaphragm from the flow of potentially harmful or dangerous powders.

Typical Applications include:

1. Lining the iris valve with a liner produces smooth powder contact surfaces resulting in a more hygienic and easier to clean assembly. This arrangement is especially good in Food, Pharmaceutical and other applications where powder hold-up is not desired.
2. Lining of the iris valve to protect the valve components from potentially harmful and corrosive powders.

2) Liners to Assist Diaphragm Opening

Where a fabric diaphragm is specified, it is always necessary to have a certain weight of material acting downwards to make it open fully. If the material has a tendency to bridge, often the diaphragm will only partially open.

If a flanged liner is hung through the valve (1) with weights of stainless steel sewn in the hem of the liner (2), this will assist in opening. (See illustration)

Liners also reduce the effort required to operate valves

Various powdered materials exert differing pressures on a diaphragm. Normally a Mucon Iris Diaphragm Valve is easily operated, but on occasions some free flowing products exert a high static load on a valve and the control lever becomes difficult to operate. This is due largely to two things:

1. The load exerted by the product forces the various layers of diaphragm material tightly together and when the control lever is operated, these try to rotate against each other.
2. It has been observed that when a Mucon Iris Diaphragm Valve operates, the material in the column adjacent to the top face of the valve tries to turn as the valve is opened.

Both of these problems can be eliminated by the use of a liner.

3) Liners to Combat Diaphragm Wear
The length of life of a diaphragm is not easily quantified because of the many variables involved such as:

1. Number of operations per day.
2. Amount of material passed per day.
3. The abrasiveness of the material.

In our experience the life of a diaphragm can vary between a few months and many years. Where the life can be measured in months it is often beneficial to consider the use of a liner.

The most frequently used liner material for combating abrasion is LINATEX rubber. This is a natural rubber with a better resistance to abrasion than steel. Where this is used it is important that a fabric diaphragm is used in the valve.

For in-line applications a double flange liner can be used.