| | | On the process side, the chemical resistance of PTFE is utilized. On the hydraulic side, the elastomer imparts favorable elastic and mechanical factors. The composite diaphragm eliminates the inherent problems of pure PTFE diaphragms. PTFE tends to cold flow when compressed between two metal parts (such as those required to industrial seal the hydraulic side from the process side). The HPD composite diaphragm features an integral "O" ring seal around the perimeter of the diaphragm, which provides a better seal between hydraulic and process fluids than conventional diaphragm materials. The HPD is capable of handling pressures up to 3025 psi and temperatures up to 300oF (with special modifications). | | |
| | | Available on: Milroyal B, Milroyal C, Milroyal D, Centrac and Maxroyal. Standard Materials of Construction: 316SS, Alloy 20, Plastic. | | |
| | | Figure 1 Diaphragm (A) and piston (C) are full forward. Mars valve (B) in forward position holds poppet valve (D) closed, preventing refill line hydraulic oil from entering the chamber. | | Figure 2 Diaphragm (A) and piston (C) are full rearward. Mars valve (B) is also rearward due to diaphragm position, thus freeing poppet (D) to open if required. Poppet (D) is shown closed, indicating hydraulic oil refill is not required. | | Figure 3 Diaphragm (A) and piston (C) are full rearward, once again forcing Mars valve (B) to its rearward position, which allows poppet (D) to open if required. Low oil volume creates a vacuum and opens poppet, permitting hydraulic fluid to enter the chamber from the refill line. | | |