Asbestos rubber plate wrapped with teflon, strength the features of anticorrossion, a widely used kind of teflon gaskets.

Teflon gaskets (PTFE envelope gaskets) are made of asbestos/rubber plate wrapped with PTFE which has anti-corrosion performance, and it DOES NOT react with concentrated acid and alkaline and strong oxidant even under high temperature.

Specifications of PTFE envelope gaskets:

Nominal(DG)	Inside Diameter(mm)	Outside Diameter(mm)	Thickness(mm)
10	15	40	1-3
15	18	45	1-3
20	25	58	1-3
25	32	68	1-3
32	38	78	1-3
40	45	85	1-5
50	55	100	1-5
65/70	76	120	1-5
80	89	138	1-5
100	108	158	3-5
125	133	188	3-5
150	162	218	3-5
200	215	271	3-5
250	273	326	3-5

Welding structure is applied for F4 when diameter is larger than 250.