US 4,054,978 A · Method for repair of valves

Abstract

A valve bonnet structure has an inner ring spaced slightly from the inner surface of the bonnet structure and secured along its lower edge portion to the bonnet. An angle-shaped member having a downturned leg lapping the ring is secured to the inner surface of the bonnet structure above the ring. For repair of the valve, an upper valve bonnet portion having the angle-shaped member thereon is removed by a cutting tool with the ring remaining in place on the lower valve bonnet portion. After repair of the valve, the upper and lower valve bonnet portions are welded together adjacent the ring with the downturned leg thereon fitting over the ring, and a seal between the leg and ring prevents fluid within the valve structure from being exposed to the welding operation.

Claims3

Dependent claims

A method of repairing a valve structure having an upper body portion with a bonnet thereon and a sleeve secured to the inner surface of the upper body portion spaced from said inner surface a predetermined distance;

said method comprising the following steps:
first cutting the upper valve body portion about a perimeter laterally spaced from the sleeve to permit removal of an upper bonnet portion from a lower bonnet portion with the sleeve shielding the interior of the valve body from the cutting operation and lapping the upper and lower bonnet portions;
then repairing the defective element;
and
thereafter welding the bonnet portions together independent of the sleeve at a position laterally spaced from the sleeve and with the sleeve shielding the interior of the valve body from the welding operation.

2 more elements

Dependencies are inferred from the claim text.

Method for repair of valves

Life of this patent

Method for repair of valves

Life of this patent

Abstract

Claims3