Definition, Quantifying and Gauging of Tightness

摘要

A leakage for fluid in a pressure vessel to flow through its sealing joint to the atmosphere is just like a leakage for electric charges in a capacitor to flow through its insulator to the ground, and hence there is a sealing law for pressure vessels that is completely similar to Ohm's law, stating the leakage current iIsubL/sub/i flowing through a sealing joint of pressure vessels is directly proportional to the pressure difference ip/i between its two ends and inversely proportional to its leak resistance iRsubL/sub/i, or iI/isubL /sub= ip/i/iR/isubL/sub. Thus it can be known according to the sealing law that the tightness or leak resistance (iRsubL /sub/i= ip/IsubL/sub/isub /sub= ipt/i/iC/i) is the product of pressure ip/i and time it/i expended on leaking a unit cubage of fluid through sealing joints under a fixed pressure ip/i and can be gauged according to the sealing theorem iRsubL/sub = p/i(ip/ii – 0.5Δp/i)iΔt//i(iΔpC/i), and the greater the value of ip/Δp/i, the shorter the time required to observe, or the closer to being done at a constant pressure and temperature the test, and the more accurate the test result, where ip/i is the test pressure, iΔt/i is the time expended on the pressure decay from ip/i to (ip – Δp/i), iC/i is the test fluid cubage.