Claims:We claim

1. METHOD OF MANUFACTURING / FABRICATION OF UNDERGROUND FIBER GLASS SINGLE / DOUBLE WALL STORAGE TANK comprising with following steps
(a) preliminary Liner (Primary shell) manufacturing using fully automatic continues mandrill filament winding machine ;
(b) on rotating steel bend (Auto-formed mandrill) fiber glass and resin applied using automatic control system;
(c) on preliminary liner developing/ producing/ creating/ manufacturing secondary shell on continues hoop-chop winding machine;
(d) this process initiated on completion of preliminary liner manufacturing with CAFW process;
(e) after mounting all necessary base material fix like monofilament, Separating net, Mylar (Polyester film) applied on Initial / primary liner to develop secondary wall on machine;
(f) secondary wall will be developed using combination of hoop roving and chop roving on winding machine;
(g) on secondary shell, developing / producing / creating / manufacturing ribs (external support) on continues hoop-chop winding machine;
(h) after secondary wall development on machine, rib fixing (external support) fix on machine and further thickness of RIB will be developed on machine;
(i) after removing complete double wall shell combined along with preliminary shell and after fixing of partition inside tank;
(j) after completion of partition fixing and inspection tank shall move to dish end fixing are and fix both pre-fabricated dish ends on tank shell end and complete lamination procedure;
(k) after completion of dish ends fixing nozzle and other accessories to be fix on tank and complete lamination as per design requirement.

2. METHOD OF MANUFACTURING / FABRICATION OF UNDERGROUND FIBER GLASS SINGLE / DOUBLE WALL STORAGE TANK as claimed in claim 1 wherein asfter completion of RIBs, Single / Double wall shell to be moved to partition fixing area and fix partition through lamination process inside tank as per tank design requirement.

Dated 14th July 2021
For,
EPP COMPOSITES PRIVATE LIMITED

Name
Designation

To,
The Controller of Patents
The Patent Office, at Mumbai , Description:

FORM 2
THE PATENT ACT 1970 (39 of 1970)
&
The Patents Rules, 2003 COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
METHOD OF MANUFACTURING / FABRICATION OF UNDERGROUND FIBER GLASS SINGLE / DOUBLE WALL STORAGE TANK
2. APPLICANT (S)
APPLICANT (S)
NAME NATIONALITY COUNTRY
OF RESIDENCE ADDRESS
EPP COMPOSITES PRIVATE LIMITED INDIA INDIA GIDC LODHIKA INDUSTRIAL ESTATE, PLOT NO 2646, KRANTI GATE MAIN ROAD,
KALAWAD ROAD, METODA
RAJKOT, Rajkot, Gujarat, 360021
PREMABLE TO THE DESCRIPTION
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

METHOD OF MANUFACTURING / FABRICATION OF UNDERGROUND FIBER GLASS DOUBLE WALL STORAGE TANK

Field of the Invention
The present invention relates to method of manufacturing / fabrication of underground fiber glass double wall storage tank for STORING various liquids, such as combustible, flammable liquids like motor fuel, Petroleum products and water, chemical, sewage water effluent water.

Background of the Invention
Tanks for the storage of liquids have been constructed in a variety of ways from a variety of materials. In one common application, the underground storage of hydrocarbons, such as gasoline and other petroleum products, the tanks have conventionally been fabricated out of steel or fiberglass, most commonly with a single rigid wall. In many applications this construction has proved reasonably satisfactory, with such tanks functioning properly for many years before requiring repair or replacement. However, the increasing age of many of the tanks currently in place is beginning to present serious environmental dangers. Many of the older steel tanks buried underground have rusted and are beginning to leak, thus releasing the petroleum / hazardous liquid materials into the ground where they may seep into and pollute underground water supplies. While rustproof, some fiberglass tanks have also exhibited leakage, causing the same problems.

One of the primary problems with leaking storage tanks has been the difficulty or inability to ascertain when or if such leaks are occurring from a given tank. Because the excavation and removal of such a storage tank, which may contain thousands of gallons of fuel, is an expensive and difficult undertaking, such an operation is difficult to justify unless there is some evidence of actual leakage.

Because of the increasing potential danger of leaking storage tanks, particularly in communities that utilize ground water for public consumption, many municipalities have implemented or plan to implement ordinances requiring the use of double wall storage tanks underground and requiring replacement of existing single wall tanks. While the installation of a conventional double wall tank in a new facility entails no great difficulty and a generally manageable increase in cost over a single wall tank, the burden of complying with such ordinances by replacing existing sound, single wall tanks with double wall tanks can be heavy. This burden has promoted the search for methods of fabricating relatively inexpensive double wall tanks. This burden has also given impetus to the search for a method of remanufacturing existing single wall tanks into a double wall assembly with means for detecting the presence of any leaks into the space between the two walls.

A number of techniques have been disclosed for converting single wall tank into double wall tank and providing such tanks with the means for detecting the presence of leaks. Such methods are shown for example in my U.S. Pat. Nos. 4,640,439, 4,644,627, 4,655,367, 4,744,137, 4,780,946, 4,780,947 and 4,817,817. Although these techniques provide for quite acceptable double wall tanks, they do require the employment of a perforated spacing material such as mesh, or alternatively, a molded spacing material that must be constructed and applied to the inner tank or alternatively the application of a release agent directly to the tank. The labor and time involved in constructing and installing these spacing materials or applying a separate coating of release agent can be significant and the need exists to reduce even further the cost of producing such double wall tanks.

Currently double wall tank made with very old process with manual hand lamination process and combination with hoop chop manual chopping on tank shell, which very conventional process. Due to manual process leakages in tank is frequently occurs.

After years of research and development in the present invention establish unique process of manufacturing Double wall Underground storage tank for petroleum tank.

Process is very unique and established in very comprehensive method to maintain smooth productivity and quality of tank.
Object of the invention
The main object of the present invention method of manufacturing / fabrication of underground fiber glass double wall storage tank with zero corrosion and high performance level in terms with elevated temperature and pressure applications. High performance materials with long service life is use to manufacturing underground storage tanks
Another object of the present invention is , where the manufacturing process of storage tanks is very fast and eco-friendly method.
The present invented method is fully automatic process particular for
preliminary shell manufacturing chances of leakages is very minimal and it directly effects environmental aspects.
Another object of the present invention has quality constancy and longer service life.

Statement of the Invention
This manufacturing process used to produce FRP (Fiber glass reinforced plastic) Composites Double wall petroleum storage tank.
Step : 1 : Inside shell (Preliminary shell) with desire thickness made through continues advancing mandrill filament winding process. (100% machine made shell ready within 45 min. time frame). During shell manufacturing, ends (dish ends) made separately on steel Mould with unique hoop chop technique.
Step : 2 Complete shell mount on specially designed automatic combine hoop- chop winding machine. Secondary shell separator with monofilament assemble on preliminary shell on machine. Complete shell fix on specially designed automatic combined hoop Chop winding machine to develop outer shell (Outer wall – Secondary shell) After developing outer wall on same machine RIB fixing and winding process carried out for getting desire thickness on tank.
Step : 3 On completion on step 2, Inside pre manufactured participation shell be fix for compartment as per tank design and requirement.
Step : 4 After fixing of compartment, dish end, nozzles and other accessories fixed on tank as per design requirement and process further for require quality testing.

Special features In present invented/ Developed Process :
? Maximum work / processed carried out by specially designed machine. It gives fast productivity with quality consistency.
? Preliminary shell manufactured through very advance technology called continues advancing mandrill filament winding process which provides uniqueness in manufacturing.
? Secondary shell also manufacture on specially design machine to provide fast productivity as well as quality consistency compare to manual process

BRIEF DESCRIPTION OF THE DRAWINGS
The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings,

Fig. 1 represents the Photo of Tank Using present invented method.

Detailed description of the invention
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompanying drawings. The invention is capable of other embodiments, as depicted in different figures as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.
To manufacturing the storage tank as shown in Fig.1 , comprising with following steps
(1) Preliminary Liner (Primary shell) manufacturing using continues advancing mandrill filament winding machine with high end technology. This process is fully automatic. On rotating steel bend (Auto-formed mandrill) fiber glass and resin applied using automatic control system.
(2) On preliminary liner Developing / producing / creating / manufacturing secondary shell on specially design continues hoop-chop winding machine. This process initiated on completion of preliminary liner manufacturing with CAFW process. In this process initial liner mount on specially design combined hoop-chop winding machine.
(3) After mounting all necessary base material fix like monofilament, Separating net, Mylar (Polyester film) applied on Initial / primary liner to develop secondary wall on machine. Secondary wall will be developed using combination of hoop roving and chop roving on specially designed winding machine.
(4) On secondary shell, Developing / producing / creating / manufacturing ribs (external support) on specially design continues hoop- chop winding machine. After secondary wall development on machine, Rib fixing (external support) fix on machine and further thickness of RIB will be developed on machine.
(5) After removing complete double wall shell combined along with preliminary shell and after fixing of partition inside tank. After completion of RIBs, Double wall shell to be moved to partition fixing area and fix partition through lamination process inside tank as per tank design requirement.
(6) On Completion of all above steps and fixing of dish ends. After
completion of partition fixing and inspection tank shall move to dish end fixing are and fix both pre-fabricated dish ends on tank shell end and complete lamination procedure. Desire thickness on dish end completed on this stage of lamination.
(7) Fixing of Nozzles, Man holes, and additional accessories as per tank drawing requirement. On completion of dish ends fixing nozzle and other accessories to be fix on tank and complete lamination as per design requirement
(8) On completion of all above tanks will go for final quality testing. After completion of nozzle and other accessories fixing tank will be transfer to testing bench for further quality inspection and testing for final dispatch clearance.

While, the invention has been described with respect to the given embodiment, it will be appreciated that many variations, modifications and other applications of the invention may be made. However, it is to be expressly understood that such modifications and adaptations are within the scope of the present invention, as set forth in the following claims.