Process for testing a vessel

• US 5,367,797 A
• Filed: 10/25/1993
• Issued: 11/29/1994
• Est. Priority Date: 10/25/1993
• Status: Expired due to Fees

• Current Assignee: Omega Environmental, Inc.
• Original Assignee: Omega Environmental, Inc.
• Inventors: Zaim, Adil Z.
• Primary Examiner(s): Noland, Thomas P.
• Assistant Examiner(s): Wiggins, John David
• Application Number:
  US08/140,957
• Time in Patent Office: 400 Days
• Field of Search: 73/37, 73/49.2 R, 73/40, 73/45.4
• US Class Current: 73/49.2
• CPC Class Codes: G01M 3/3263 using a differential pressure detector G01M3/3245, G01M3/3272 take precedence

Abstract

Establishing that pressure-influencing factors other than leakage of gas have stabilized before testing the integrity of a vessel in a system including the vessel, a reference vessel that can be connected to and isolated from the vessel, a common source of pressurized gas, a gauge to measure the difference between the vessel pressure and the reference vessel pressure and a computer capable of recording a series of pressure-difference measurements and mathematically manipulating them, the method including equalizing the pressures in the two vessels, then isolating them from each other for a preselected time period, then recording the pressure difference between them at the end of the time period, again equalizing the pressures and repeating that sequence until the pressure difference at the end of two consecutive time intervals is the same, thereby establishing that pressure-influencing factors other than leakage have stabilized.

Claims

1. A process for establishing the stability of factors influencing pressure in a process for testing the integrity of a vessel employing a system including said vessel, a reference vessel, a fluid passageway including a valve between said vessel and said reference vessel, means to supply gas at a test pressure to both said vessel and said reference vessel from a common source, and means to measure the difference between the gas pressure in said vessel and said reference vessel said process comprising:

introducing gas into said vessel and said reference vessel at the same pressure from said common gas source with said valve open until the difference in pressure between said vessel and said reference vessel is zero,

isolating said vessel and said reference vessel from said gas source,

closing said valve,

recording the value of the difference in pressure between said pressure vessel and said reference vessel after passage of a preselected time interval,

opening said valve at the end of said preselected time interval for a time sufficient to equalize the pressures in said vessel and said reference vessel and then closing said valve,

recording the value of the difference in pressure between said vessel and said reference vessel after the passage of another preselected time interval,

repeating the steps of opening said valve to equalize pressures and closing said valve for further preselected time intervals and recording the value of the pressure difference until the pressure difference between said vessels, at the end of two consecutive time intervals is substantially zero, whereby pressure changing factors other than leakage are established as stabilized, and closing said valve for a time period sufficient to establish the integrity of said vessel as indicated by changing pressure difference indicated by said means to measure pressure difference.

2. The process of claim 1 wherein said system includes a computer having means to receive and store signals representative of the difference in pressure in said vessel and said reference vessel, having means to actuate said valves to open and close, having clock means and having means to mathematically manipulate data representative of pressure difference values, said computer measuring each time interval, recording pressure difference values at the end of each preselected time interval, opening said valve at the end of each preselected time interval, closing said valve at the start of each preselected time interval and identifying the end of a second consecutive time interval at which said pressure difference is substantially zero.