Drinking Water Approval for Diaphragm Valve
Drinking water is the most closely monitored substance for human consumption and all materials, plant and system components that come into contact with drinking water are subject to strict regulations. GEMÜ has used diaphragm valves with an EPDM diaphragm (code 14) for such applications in the past. The approval for this diaphragm could not be extended after revision of the relevant standards and directives. We have therefore developed a new diaphragm code 18 (EPDM) for drinking water applications and had it certified by the authorities in accordance with KTW recommendations 1.3.13 of the German Federal Health Office.
In addition to the certification of the new diaphragm we have also had certain versions of the GEMÜ 675 diaphragm valve certified by the DVGW. Complying with the requirements of DIN 3546-1 (10/2002) and DVGW Work Sheet W 570-1 (4/2007) the valves have been certified in nominal sizes DN 25 - 100 , but nominal sizes DN 125 and DN 150 of the same version are also available. The temperature limits are 0°C - 80 °C, the maximum permissible operating pressure is 10 bar. The valve bodies in nominal sizes DN 25 - 50 are in cast bronze, the pipe connection is a RP threaded socket to DIN EN 10226-1. Nominal sizes DN 65 - 150 are available with flanges to EN 1092, PN 16, form B, length EN 558 series 1 in GJL-250 (GG 25) material with an Epoxy coating with KTW (contact with drinking water) approval. This special coating is also approved by the DVGW, as is the company that carries out the coating. The valves are used in municipal water treatment and drinking water supply applications, among others.