FAQ: Can cement-mortar linings be repaired in the field?
Repair is achieved by first cutting out the defective or damaged lining to the metal so that the edges of the lining not removed are reasonably perpendicular to the pipe wall or slightly undercut. A stiff mortar is then prepared, containing not less than one part of cement to two parts of sand, by volume. This mortar is applied to the cutout area and troweled smooth with adjoining lining. To provide for proper curing of patches by preventing too rapid of a moisture loss from the mortar, the patched area is normally seal-coated immediately after any surface water evaporates, or alternatively the area is kept moist (e.g. with wet rags or burlap over the area or with the ends of the pipe or fitting taped over with plastic film, etc.). Of course, in potable water-related applications, no patch or curing components should be used in the repair that would negatively affect health or water quality.
FAQ: How long of a pull can be made?
There are many variables that determine the length of pull. The type of soil, size of equipment, amount, concentration and viscosity of the bentonite in the drilling mud are just a few of the variables that can determine the length of the pull. The longest pull to date was 2120 feet of 12” TR FLEX® pipe.
FAQ: How much Bentonite should I add to the drilling mud in the ream and pull back process?
Soil conditions can vary widely and change dramatically within the length of the intended pull, it is for this reason that consideration be given to take soil samples at regular intervals along the intended bore-path at the depth of the bore. This information would enable the drilling operator to adjust the bentonite mixture, viscosity and add any other stabilizing additives as per the bentonite manufactures recommendations.
FAQ: How should the pipe be wrapped if rock is encountered in the bore path?
Double poly-wrap is recommended either with the first layer being the low-density poly with high-density over the outside or double wrapped with low-density.
FAQ: What benefit does spiral winding the tape along the barrel of the pipe provide?
Spiral winding is easier to do in a muddy trench and also does not allow the drilling mud to build-up underneath the poly-wrap causing it to balloon. All over-lapped edges of the poly-wrap should be taped except for the over-lapped poly along the length of the barrel, where the spiral winding is sufficient.
FAQ: What lining is typically used for Ductile Iron pipe transporting seawater?
Double thickness cement mortar lining in accordance with ANSI/AWWA C104/A21.4, Section 4.7.2., with seal coat in accordance with section 4.11. The cement in the cement mortar lining shall conform to ASTM C150, Type V. The internal joint areas coming in contact with the seawater, the "wetted areas", should be coated with Induron PE-54 epoxy or they can be wrapped with Denso tape. Denso tape can be purchased through DENSO NORTH AMERICA, INC. in Houston, TX - Phone No. 281-821-3355 or www.densoa.com.
FAQ: Can I disassemble a TR FLEX® or FIELD LOK 350® gasket joint?
Yes. The TR FLEX® joint is easily disassembled by following the assembly instruction found in our TR FLEX® Pipe and Fittings brochure. The FIELD LOK 350® gasket requires a disassembly kit that can be purchased through your U.S. Pipe Representative.
FAQ: When the pipe is jacked, will it stay round?
If possible, the pipe can be inserted to make–up the joint, after assembly the jack can be removed. If the pipe will be inserted into a Mechanical Joint bell, the gland can be slid over the end to hold the pipe round while the joint is made. TYTON JOINT® and TR FLEX® bells are designed to round the pipe as long as the pipe will start into the throat of the bell. Once the pipe is pushed past the gasket it will seal.
FAQ: Where can TR FLEX GRIPPER® rings be used?
Gripper rings can be used to complete closures and are not recommended for use in the pulling/pull back process.
FAQ: Where can I find information on safe Ductile Iron pipe handling when unloading from trucks and/or railroad cars?
This information can be found in U.S. Pipe's guide Safe Packaging and Shipping (STD-550) and also the Installation Guide for Ductile Iron Pipe, published by the Ductile Iron Pipe Research Association (DIPRA). Copies can be obtained from your local U.S. Pipe Sales Representative.