Claims:WE CLAIM

1. A Portable Fixture for tank / compartment isolation required for Air Pressure Testing (APT) during the manufacture of ship / vessel comprising of :
a steel disc, a stud, a neoprene rubber gasket, a spacer and a nut, a fitment for closing the opening hole, wherein – one end of stud is fixed with the disc centre and other end is threaded to hold a nut while the neoprene rubber gasket is cladded with the annular portion of disc.

2. The Portable fixture as claimed in claim 1, wherein the said spacers are configured for providing an air tight integrity to fixture by tightening the assembly to deck / Bhd where it is fitted.

3. The portable fixture as claimed in claim 1, wherein the fitment for closing the opening hole from the side which is inside of the compartment.
, Description:PORTABLE FIXTURE FOR TANK / COMPARTMENT ISOLATION IN SHIPS

FIELD OF INVENTION
The present invention relates to development of portable fixture to achieve isolation of tank / compartment of ship for doing Air Pressure Testing (APT). More particularly, the present invention discloses a fixture employing minimal components viz a steel disc, a stud, a neoprene rubber gasket, a spacer and a nut, for naval ship and merchant vessel construction.

BACKGROUND ART

Leak testing of tanks and compartments is prerequisite & critical activity prior launching ships. It is therefore recommended to timely accomplish all leak testing activities of ship. With the present arrangement followed it is cumbersome and time consuming to achieve 100 % sealing of tank or compartment within very short time available. Hence, the manpower handling this activity has a tedious but crucial activity to complete which is always an issue at hand.

Firstly, in any leak testing operation we need to isolate the subject tank or compartment from adjacent space. This is achieved by closing all the openings or piercing points of deck / bulkheads by blank pieces. These blank pieces are placed on opening and tack welded all around. Now to make it leak proof a sealant putty (a paste like substance) is applied all around blank pieces and allowed for almost 12 hrs to solidify completely (Refer to Fig. 1). With this invention, the earlier process of applying sealant putty around the opening and welding of steel disc around the opening obviated completely.
After complete isolation is achieved, the enclosed space / tank is pressurised with compressed air to desired pressure as per testing plan. The pressurised tank is retained to desired pressure for about an hour and simultaneously checked for leaks if any. Leaks detected are subjected to repair and the tank is re-pressurised to check for leak. This cycle is repeated until no leak is observed. This is all about leak testing of tanks and compartments by existing arrangement.

SUMMARY OF INVENTION
The primary objective of the present invention is to provide a safer and standard method for which a new innovative fixture was designed which enabled faster tank isolation and required lesser manpower for deployment.
Therefore such as herein described there is provided a portable fixture comprising a steel disc, a stud, a neoprene rubber gasket, a spacer and a nut, wherein – one end of stud is fixed with the disc centre and other end is threaded to hold a nut while the neoprene rubber gasket is cladded with the annular portion of disc.
In an embodiment there is provided spacers configured for providing an air tight integrity to fixture by tightening the assembly to deck / bhd where it is fitted.
In another embodiment the portable fixture includes fitment for closing the opening hole from the side which is inside of the compartment.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 illustrates the pictorial view of existing way of sealing by using sealant paste as prior art;.
Fig. 2 illustrates the sketch of fixture in accordance with the present invention;
Fig.3 illustrates the pictorial view of fixture vin accordance with the present invention;
Fig.4 & 5 illustrates the fixture in fitted condition in tank or compartment of ship in accordance with the present invention.

DETAILED DESCRIPTION

The design and methodology devised for isolation of tank for undertaking APT is simplistic and has also resulted in savings due to lesser man-days and increased safety.

The present invention has a wide range of Industrial application both for naval ship and merchant vessel construction. This system of isolation of tank prior to APT will reduce the overall tank testing time and improve the safety of work

In the current invention, the tank isolation is carried out by specially designed fixture as shown in the figure-2, 3, 4, and 5. The fixture consists of a blank plate with stud welded at the centre. Rubber gasket is cladded on the annular space of blank plate fitted with stud. The process of sealing the opening on Bhd / Deck is attained such that the blank plate along with rubber cladding will assemble on the inner surface of the opening while the stud will be protruding out through the opening.

A spacer along with nut is on the other side of opening in the same assembly and gets tightened to Bhd / Deck plate opening by nut on other side making it an air tight joint.

Once all the opening in the tank is closed by the above mentioned fixture, the tank can be pressurised for 1 hr & thereafter carried out leak test successfully.

Although the foregoing description of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration by way of examples and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.