A unique insertion valve design has made a big difference for crews that work on iron, plastic, ductile, AC and other common pipe materials. Preparation and install times have been reduced and total cost per valve has been improved by a tested and efficient concept: a slot access resilient wedge gate that doesn't sever the line, doesn't cause restraint problems and provides a simpler and easier procedure.
Until recently this slot-access insertion valve hadn't been applied to a steel pipeline (in sizes over 12" (300mm)) due to the differences in OD of steel sizes as compared to most other pipe materials. A simple solution was devised by manufacturing custom steel saddles to create a welded-on "sleeve." The sleeve is composed of half-cylinder sections that bring the OD dimension into agreement with other pipe materials and permits the use of standard gaskets sets.
Once the new enhanced diameter section is completed, the valve insertion process takes three simple steps. First, the pipe section is wrapped with low-friction tape, the gasket set is thoroughly lubricated, and the valve castings are secured to the pipe section. Second, the temporarily mounted milling machine, guide controls, and chip-flush system are attached and used to create a 120-degree access slot in the host pipe. Third, the temporary equipment is removed, the valve bonnet is attached, the fittings are torqued to final values, and the valve is actuated as needed. If used as a line stop, the valve bonnet may be easily replaced with a blind flange at a future time. The bonnet is then available for other use.
The entire process may be completed under pressure and with no interruption of service. An internal isolation slide valve that is built into every EZ™ valve avoids procedures common to other insertion valve designs. These include the need for a bulky and costly separate isolation system, the heavy-lifting equipment needed to repeatedly apply and remove the isolation device, plus the extended time required for the multiple change-outs.
Steel pipeline insertion valves can now be installed with the economy, speed, convenience, and reliability that other pipe materials have enjoyed. Typical valve install times are about one hour for smaller sizes (up to 12" (300mm)) and four hours for 14" (350mm), 16" (400mm), 20" (500mm), 24" (600mm). As is true with all other pipe materials, costly restraint operations are avoided due to a design that maintains the integrity of the pipe by not requiring dropping a coupon that totally severs the host pipe.
For details about slot-access insertion valves, contact Advanced Valve Technologies, Inc (877-489-4909 or www.avtfittings.com) and ask about the EZ™ line of valves serving 4" (100mm) through 12" (300mm), 14" (350mm), 16" (400mm), 20" (500mm) and 24" (600mm) nominal sizes.
This sleeve was developed to adapt 16" (400mm) steel OD pipe (16.00) to DI OD pipe 17.40. It is welded to the 16" (400mm) steel pipe, making the OD 17.40. This allows us to use our standard gaskets.
Our first three installations (2 on steel pipe and one on ductile iron pipe) have performed perfectly.
Now steel pipelines can benefit from a tested and advanced insertion valve design that has become the favored choice of water professionals.
Left to Right: Sleeve is welded to existing pipe; Valve body is secured in place; 120° slot is cut across top of pipe; Cutting tool is removed and bonnet is lowered into place; Bonnet is secured onto valve body.