Scored reverse buckling rupture disk manufacturing method

• US 4,441,350 A
• Filed: 12/15/1981
• Issued: 04/10/1984
• Est. Priority Date: 12/15/1981
• Status: Expired due to Term

• Current Assignee: BS&B Safety Systems LLC (International Systems & Controls Corp.)
• Original Assignee: BS&B Safety Systems LLC (International Systems & Controls Corp.)
• Inventors: Short, Edward H. III, Allen, Jerome D., Wood, deceased, Loren E.
• Primary Examiner(s): Gilden, Leon
• Application Number:
  US06/330,809
• Time in Patent Office: 847 Days
• Field of Search: 72/54, 72/55, 72/56, 72/57, 72/58, 72/60, 72/61, 29/421 R, 29/157.1 R
• US Class Current: 72/55
• CPC Class Codes: B21D 53/80 dustproof covers; safety covers
• CPC Class Codes: F16K 17/1606 of the reverse-buckling-type F16K17/1633 takes precedence

Abstract

The present invention relates to improved methods and apparatus for manufacturing scored reverse buckling rupture disks. The scores on the disks radiate outwardly from central portions thereof toward the peripheries thereof and have known depths and depth variances.

Claims

1. An improved method of manufacturing a group of scored reverse buckling rupture disks of desired reversal rupture pressure from sheet metal comprising the steps of:

(a) dividing said sheet metal into a plurality of sections;

(b) forming a concave-convex dome in each of said sheet metal sections; and

(c) forming identical scores of predetermined depth on a surface of each of said concave-convex dome portions of said sheet metal sections thereby creating identical lines of weakness therein, said scores radiating outwardly and having a greater depth, at the central portions of the radii of said concave-convex dome.

2. The method of claim 1 wherein said scores are deeper at the central portions of said concave-convex dome portions of said sections than at the peripheries thereof whereby said concave-convex dome portions have less ability to resist reversal at the central portions thereof than at the peripheries thereof.

3. The method of claim 2 which is further characterized to include the steps of:

(d) reforming said scored concave-convex dome portions of said sections to increase the crown heights thereof; and

(e) annealing said sections to relieve stresses therein.

4. An improved method of manufacturing a group of scored reverse buckling rupture disks of desired reversal rupture pressure from sheet metal comprising the steps of:

(a) dividing said sheet metal into a plurality of sections;

(b) forming a concave-convex dome in each of said sheet metal sections by applying fluid pressure on a circular area of one surface thereof;

(c) forming identical scores of known depth on a surface of each of said concave-convex dome portions of a group of said sheet metal sections, said scores radiating outwardly and having a greater depth at the central portions of said concave-convex dome portions of said sections;

(d) applying increasing fluid pressure on the concave side of said concave-convex dome portion of one or more of said group of scored sections until said dome portion ruptures thereby determining the tension rupture pressure of said scored sections;

(e) applying increasing fluid pressure on the convex side of the concave-convex dome portion of one or more of said scored sections until said dome portion reverses itself and ruptures thereby determining the reversal rupture pressure of said sections;

(f) repeating steps (c) through (e) on additional groups of said sheet metal sections while varying the depth and depth variance of said scores formed in accordance with step (c) until a desired reversal rupture pressure is obtained in step (e) and the ratio of tension rupture pressure to said reversal rupture pressure is equal to or less than 1.5; and

(g) carrying out step (c) on each of the remaining sheet metal sections using the depth and depth variance of scores which resulted in said desired reversal rupture pressure and a ratio of tension rupture pressure to reversal rupture pressure equal to or less than 1.5.

5. The method of claim 4 wherein said scores are deeper at the central portions of said concave-convex dome portions of said sections than at the peripheries thereof whereby said concave-convex dome portions have less ability to resist reversal at the central portions thereof than at the peripheries thereof.

6. An improved method of manufacturing a group of scored reverse buckling rupture disks of desired reversal rupture pressure from sheet metal comprising the steps of:

(a) dividing said sheet metal into a plurality of sections;

(b) forming a concave-convex dome in each of said sheet metal sections by applying fluid pressure on a circular area of one surface thereof;

(c) forming identical scores of known depth on a surface of each of said concave-convex dome portions of a group of said sheet metal sections, said scores radiating outwardly and having a greater depth at the central portions of said concave-convex dome portions of said sections

(d) applying increasing fluid pressure on the concave side of said concave-convex dome portion of one or more of said group of scored sections until said dome portion ruptures thereby determining the tension rupture pressure of said scored sections;

(e) applying fluid pressure on the concave side of said concave-convex dome portions of the remaining of said group of scored sheet metal sections at a level in the range of from about 85% to about 95% of said tension rupture pressure;

(f) annealing said scored sheet metal sections to relieve stresses therein;

(g) applying increasing fluid pressure on the convex side of the concave-convex dome portion of one or more of said scored sheet metal sections until said dome portion reverses itself and ruptures thereby determining the reversal rupture pressure of said sections;

(h) repeating steps (c) through (g) on additional groups of said sheet metal sections while varying the depth and depth variance of said scores formed in accordance with step (c) until a desired reversal rupture pressure is obtained in step (g) and the ratio of tension rupture pressure to said reversal rupture pressure is equal to or less than 1.5; and

(i) carrying out steps (c), (e) and (h) on each of the remaining sheet metal sections using the depth and depth variance of scores in step (c) which resulted in said desired reversal rupture pressure and a ratio of tension rupture pressure to reversal rupture pressure equal to or less than 1.5.

7. The method of claim 6 wherein said scores formed in said rupture disks in accordance with step (c) are formed in a manner such that said scores are deeper at the center of the dome portion than at the periphery thereof.

8. The method of claim 7 wherein the annealing of said sheet metal sections in accordance with step (f) comprises heating said sheet metal sections to a temperature in the range of from about 1500°

F. to about 2000°

F. for a period of time in the range of from about 2 minutes to about 5 minutes.