CSST in Underground Gas Piping Applications. Underground Gas Piping

CSST in Underground Gas Piping Applications

Is CSST the right choice for my underground gas piping project? Corrugated Stainless Steel Tubing, or CSST, has dramatically changed the field of Gas Piping. Although CSST has a relatively high product cost, the time savings in many applications more than make up the difference with saved labor cost. In retrofit gas piping installations, pulling a flexible gas line under the house can cut hours of labor from the job, making gas line additions much more affordable than years past even with the higher material cost. Another great benefit of CSST, there are only gas fittings at each end of the line, greatly decreasing the chance for a leak or bad fitting.
Recently, many states have recognized the ability of CSST to be used in underground gas piping installations. CSST cannot be directly buried under any circumstance! Also, in order to purchase CSST, you must be a licensed Gas Contractor and have had training with the particular brand you would like to use. CSST for use in underground gas piping installations must be sleeved in suitable conduit, either electrical conduit or ABS. Larger diameter’s are necessary to pull the CSST thru the line, generally 3″ conduit is used. On the end of the line feeding your outdoor gas appliance, the end must be capped. Drilling a hole thru the cap and using a round CSST gas termination mount is the preferred method. On the opposite end, a “Tee” with a downturned elbow in the middle must be installed to allow the conduit to vent. CSST is much more expensive by the foot then poly underground gas piping, so it is only practical in shorter underground lengths, generally 20′ or less.
Talk to your Gas Contractor about the most cost effective method for your project. Do NOT under any circumstances allow a shady gas piping contractor to install black iron underground. This is an extremely dangerous practice that unfortunately we do still see on occasion.