These  diaphragms  are  made   in  a  rubber-coated  fabric and  drawn  by  means  of  a
thermoforming  process.  The  rubber-coated  fabric consists  of  a  fabric  insert  coated
on both sides by a thin sheet of rubber (Fig. 2).

Compared to the concave membranes, these diaphragms can work at higher pressures.

Technical features:

-          Available fabric inserts in:  nylon, polyester, cotton, viscose, and polyaramide
fibres (for  high temperatures);

-          Available  rubber coating:  nitrile  rubber,  neoprene,  or  FKM  (for  special
applications).

-         Thickness: normally, between 0.2mm to 1mm.

-         Addition seal available  in the flanging area  (to make the thin rubber sheet  stronger):   the seal can be obtained with a O-ring type rubber section (Fig. 3) or with gasket in cellulose fibre (Fig. 4)

Cervellati also sell the followings rubber-coated fabrics:

-          Thickness 0.20 mm: NBR + cotton

-          Thickness 0.20 mm gasmeter: black Eco + cotton – polyester

-          Thickness 1 mm: black NBR + Nylon 210