Abstract: Provided herein is a pipe joint of a relatively small joint diameter for use under ultrahigh pressure conditions. The pipe joint includes first and second joint members having mutually communicating fluid passages; and a gasket interposed between abutting end surfaces of the first and second joint members. The first and second joint members have ring-shaped seal projections formed at the abutting end surfaces thereof. The pipe joint satisfies a coefficient F of 0.4 or less in the following formula (1). F=(D32?D12)/(D42?D22), ??Formula (1): where D1 represents the inner diameter of the first and second joint members, D2 represents the inner diameter of the gasket, D3 represents the diameter of the seal projections, and D4 represents the outer diameter of the gasket.

Abstract: A jig for selecting a valve part number or a joint part number representing respective selected conditions required for selecting a valve or a joint comprising: a substantially rectangular base plate defining an inner space, and several sliding gauges laterally arranged in the inner space to slide in a longitudinal direction of the base plate, each of the sliding gauges comprising a condition description area including several conditions thereon from which the selected condition is determined, and a symbol description area including several symbols thereon, both the conditions and the symbols arranged in the sliding direction, several condition selecting windows laterally arranged, each of the condition selecting window being configured to expose one of the selected conditions, several symbol selecting windows laterally arranged, each of the symbol selecting window being configured to expose one of the selected symbols.

Abstract: A jig for selecting a valve part number or a joint part number represented by a combination of selected symbols representing respective selected conditions required for selecting a valve or a joint comprising: a substantially rectangular base plate defining an inner space, and a plurality of linear sliding gauge laterally arranged in the inner space to slide in a longitudinal direction of the base plate, the sliding gauge comprising a condition description area including a plurality of conditions thereon from which the selected condition is determined, and a symbol description area including a plurality of symbols thereon, both the conditions and the symbols arranged in a sliding direction of the sliding gauge, a plurality of condition selecting windows laterally arranged on a top of the base plate, each condition selecting window configured to expose one of the selected conditions, a plurality of symbol selecting windows laterally arranged on the top of the base plate longitudinally apart from the condition

Abstract: A pipe coupling 30 comprises a tubular body 31 for a pipe 32 to be inserted in through the rear end thereof, a front ring 33 and a back ring 34 to be fitted around the pipe 32 projecting from the rear end of the body 31, and a cap nut 35 for tightening up the front and back rings 33, 34 to fix the pipe 32 to the body 31. The back ring 34 is made of an alloy comprising, in % by weight, 0.001 to 0.01% of C, up to 5% of Si, up to 2% of Mn, up to 0.03% of P, up to 100 ppm of S, up to 50 ppm of O, 18 to 25% of Cr, 15 to 25% of Ni, 4.5 to 7.0% of Mo, 0.5 to 3.0% of Cu, 0.1 to 0.3% of N, and the balance substantially Fe and other inevitable impurities.