The Perpetua™ Model 7B

One filter for the whole house. Installed on your cold water main, the Perpetua removes sediment, rust, silt, and turbidity from every tap. Its ceramic element is cleaned, not thrown away. Its Cycle Head backwashes it automatically every night. You will forget it is there. That is the idea.

Fig. 1. Perpetua Model 7B, cutaway. (1) Brass head with bypass lever. (2) Cycle Head with timer and backwash valve. (3) Perpetua Element with prefilter wrap. (4) Bowl. (5) Guarantee faceplate. (6) Drain plug.

Specifications

The Element

The Perpetua Element is the reason the Perpetua exists. Lorraine Wendorf developed it between 1974 and 1977 in the back of the original Mill Street shop: a sintered ceramic candle, fired here in Kessel Falls, with a silver-impregnated core that keeps the wet ceramic sweet. Sediment stops at the surface. Scrub the surface and it is new again. A cotton prefilter wrap catches the coarse material and is replaced a few times a year. Nothing is thrown away except the wrap.

The Cycle Head

Any filter clogs. Ours cleans itself. Once a day the Cycle Head reverses the flow through the element for ninety seconds and sends what it finds down the drain. The element stays open, the pressure stays up, and the cleaning interval stretches to months. The Cycle Head was Vern's idea, and the reason we could put the word continuous on the faceplate.

Models

Model 7 (1978-1993): cast bronze bowl. The original. Thousands still in daily service. Model 7B (1994-present): cast aluminum bowl with epoxy lining, improved Cycle Head with low-voltage motor. Same element, same guarantee, same faceplate. Ask your dealer.