Prefabricated valve lining

Covering panels 600 x 300 mm made of soft white wool felt, 2 or 3 mm thick, bonded to medium gasometer leather (our cat. no. B7160) using high-quality self-adhesive film. Total covering thickness approx. 3 or 4 mm.

We are happy to provide you with the following information about our bonding and its possible use:
When bonding the felt covered with self-adhesive film from the manufacturer to the gasometer leather, we take particular care to ensure that the adhesive strength of the self-adhesive film is retained. For this reason, we additionally roll the leather covering after bonding so that the adhesive film on the felt bonds optimally with the leather. When applying the gasometer leather we use, which has been sanded on the adhesive side by the leather manufacturer, we take care to remove any sanding dust.
For your use of this inexpensive valve covering, which is valued for its uniform softness, please note the following additional information, as we have to exclude a guarantee for this product:
Unfortunately, we have recently received feedback that valve facings have separated between the felt and the adhesive foil during use, resulting in "howling". This is very annoying and we still do not have a proper technical explanation.
As this high-quality adhesive film is applied to the felt by our supplier, we are unable to assess it. In tests, however, we do not have the impression that it is too weak, as ultimately any felt can be removed from an adhesive surface (sk-film, bookbinding glue, thin white glue, etc.). It is noticeable that the problem has so far occurred with valve slot widths of over 15 mm and heavy tearing. Presumably the wind causes the leather covering to bulge more strongly over the access of the soft felt in the middle of the valve slot and causes this problem.
As there are many different valve situations, we cannot give any generally valid instructions or guarantees and ask you to carry out your own tests or use your own experience. Thank you very much for your attention!