<p>A thermal expansion valve (1) for a refrigeration system comprises a working element (9) with a diaphragm (15) clamped between a cover plate (12) and a cover ring (10). The diaphragm is a multiple-diaphragm comprising two or more individual diaphragms (16, 17). This makes the multiple-diaphragm more flexible than a single diaphragms and increases the lifetime of the diaphragm. The individual diaphragms are separated by an anti-friction layer to protect against tear, the anti-friction layer can be grease or oil placed between the individual diaphragms or it can be a layer of coating on the diaphragms.</p>
