Twenty-Four Years and Still Sealing Pipe Penetrations

The Link-Seal Model-C sealing element is manufactured from EPDM black rubber that handles temperature ranges -40 to +250°F. During installation, the rubber link is compressed to fill the annular space between the pipe's outer diameter (OD) and the wall penetration by means of pressure plates molded from Reinforced Nylon Composite and formed so that pressure is transferred to the sealing element uniformly. As a hydrostatic seal, Link-Seal modular seals are rated at 20 psig (40 feet of head).

Link-Seal modular seals were installed in 1979 by the Limbach Co., on the original Ypsilanti Wastewater Treatment Plant. Michael Jessee, the plant maintenance superintendent, said that the more than 100 pipe seals in use throughout the plant have shown no noticeable leaks in the 18 years he has been at the plant. This is due in part to the design of the 15 available models of Link-Seal modular seals capable of handling from a 1/2"-OD pipe up to a 120"-diameter pipe.

These seals are designed for use as a permanent seal. Seal elements are specially compounded to resist aging and attack from ozone, sunlight, water and a wide range of chemicals. The carbon bolts and nuts feature a zinc dichromate proprietary organic corrosion inhibiting coating. For extreme treatment plant water conditions, 316 stainless steel bolts and nuts are used.

For the Ypsilanti Wastewater Plant's 2002, $100 million plant expansion, the consultant engineer Tetra Tech MPS of Ann Arbor, Mich., specified Link-Seal modular seals as a prime wall penetration sealer. Marty Schlitt, project manager for the John E. Green Co., the awarded mechanical contractor, said that there would be more than 100 sealing applications through 48" pipe with multiple cored holes. Schlitt prefers the Century-Line sleeves for the cast in-place applications. These HDPE sleeves will eliminate rust stains on the walls resulting from moisture condensing and dripping from the original installed steel sleeves. HDPE also provides excellent resistance to acids, alkalis and other organic solvents found in treatment plant environments.