摘要:
A composite pipe has a metal conduit sandwiched between inner and outer conduits of PVC/CPVC, each of which are adhesively secured to the interlaying metal conduit with a dried, solvent-free thin layer of a thermosetting bilayer adhesive which provides a bond with the metal, which bond fails in cohesive failure. Narrowly defined limits on the thickness of each conduit are found to provide a bendable composite pipe with an aluminum interlayer; and to provide a rigid non-bendable composite pipe with a steel interlayer. Making the composite pipe which meets required ASTM and NSF test considerations requires unexpectedly critical process steps. A process for making the pipe is disclosed, as are PVC/CPVC fittings which allow lengths of pipe to be solvent-cemented in them so as to seal the terminal ends of the pipe against infusion of fluid under pressure in the pipe, thus preventing delamination.
摘要:
PVC and/or CPVC tubing and/or pipe is adhesively-secured at one end with a pipe fitting telescopably mated with each other with a uniquely effective epoxy adhesive. The resulting pipe joint is fluid-tight. PVC pipe joints meet the requirements of ASTM F1970; CPVC pipe joints meet the requirements of ASTM D2864. Such PVC and CPVC piping systems are chosen to carry cold and hot aqueous streams respectively, under pressure and elevated temperature in continuous service, both, in industrial and domestic piping systems. Such piping systems also carry more corrosive fluids for specified duration, less than 50 years.
摘要:
CPVC pipe in diameters in the range from 15 mm (0.5 inch) to 15.24 cm (6 ins), to carry hot and cold aqueous streams under 690 KPa (100 psi) pressure and 82.2°C (180°F) in continuous service, is extruded from a compound in which the CPVC has a high CI content in range from 66.5%-70%, when modified with either of two specific impact high rubber modifiers in an amount greater than 5 parts but no more than 6 parts per 100 parts of CPVC. Extruded CPVC pipe provides a HDB measured according to ASTM D2837-01 which is 25% or more greater than that required for commercial pipe as specified in ASTM D2846. As a result, both SDR-11 and SDR-13.5 pipe are produced which provide a HDB greater than 1250 psi (8.62 MPa) at the 100,000 hr intercept.
摘要:
An aqueous fire sprinkler fluid containing low carbon number carboxylate salts for freezing point depression is described. The salts may be used in conjunction with glycols. The salts decrease the combustibility of the glycol containing fluids and give lower viscosity than higher glycol fluids, both benefitting fire sprinkler systems. These salt solutions are friendly to metal and CPVC pipes and are thus useful for fire sprinkler systems by not causing environmental stress cracking of the CPVC components and not being corrosive to the metal parts.
摘要:
Fire sprinkler system comprising a network of CPVC pipe lengths in which at least some of the pipe lengths are interconnected with mechanical devices having resilient sealing members that are chemically compatible with the CPVC composition. Repairs and system modifications can be made without the use of solvent cement. In-line joints are formed with a coupling device including a pair of arcuate coupling segments having a first end, a second end, and an interior concave surface extending between the first end and the second end. A longitudinal channel extends along the concave surface. At least one mechanical fastener is operative to detachably connect the pair of coupling segments. A resilient annular seal is located within the longitudinal channel of each segment. A branching device connects a branch pipe to a main pipe through an orifice in the main pipe utilizing a saddle-like sealing member.
摘要:
An aqueous fire sprinkler fluid containing low carbon number carboxylate salts for freezing point depression is described. The salts may be used in conjunction with glycols. The salts decrease the combustibility of the glycol containing fluids and give lower viscosity than higher glycol fluids, both benefitting fire sprinkler systems. These salt solutions are friendly to metal and CPVC pipes and are thus useful for fire sprinkler systems by not causing environmental stress cracking of the CPVC components and not being corrosive to the metal parts.