FIELD OF THE INVENTION

This invention relates to a method for conducting Real Time Radiography (RTR) test of welding joints on tubes of different diameters.

BACKGROUND OF THE INVENTION
Steam generators used for power generation have several components like super-heaters, re-heaters, economisers and water wall panels. Most of the tube raw materials supplied in length of 10meters by domestic as well as foreign tube suppliers. In re-heater, economisers and super-heater coils have design requirement up to 40 meters length.so, in order to get increase length of tubes, “tube to tube butt welding machine” simply known as Straight Tube Butt welding machine (STBW) is used. Several materials grades are used in boiler tubes for example carbon steel (Gr A1, Gr C), Low alloy steel (T11, T12 & T23), High alloy steel (T23, T91, T92) and stainless steel (347H, Super304H).
After welding of tubes in STBW machine, the welded tubes are checked for defects through Real Time Radiography method. Real time radiography is a Non-destructive method of checking the weldments of tubes by X- Ray radiation passed through the weldments. The welded tubes are conveyed to RTR room through roller conveyor system. There tubes are checked throughout 360° by rotating mechanism to rotate the welded tubes.
The total build-up length of the tubes after welding in STBW machine is from 24 meter to 72 meter. That could be checked in RTR by NDTL operator without any additional requirement to handle the welded tubes because of conveyor and roller system. But in few cases, to weld some spare tubes of having dissimilar material specifications like various

diameter, thickness or grades that cannot be welded in site works. The build-up length after welding is only about 400mm in the above cases that is 200 length of various diameter, thickness or various grade tubes are welded. Approximately 5000 joints per year required for spare plan and repair work. In site work, the combination of tubes having different diameter, thickness and different materials welding is difficult and not possible in some cases. So that welding that dissimilar joints in shop floor require additional settings.
Prior art techniques show that it is very difficult to handle the short length tubes to check the RTR result. This short length tubes cannot be held in the rotating mechanism provided inside the RTR room to check the tubes. Hence this requires manual work. However, it is not possible to enter inside the RTR room X-ray unit, because of radiation. Hence all the short length welded tubes need to be sent to manual X-ray test. Thus time delay is increased to test in manual X-ray test because the action has to be completed during night time only. While taking manual X-ray test, the radiation effect is up to 100 meter surroundings such that production of joint welding is in limited numbers due to suspecting defects.
Accordingly, there exists a need in the art to develop an apparatus and method for conducting RTR test of weldments of short length tubes of different diameter.
OBJECTS OF THE INVENTION
An object of the invention is to propose an apparatus for conducting RTR test of weldments of short length tubes of different diameter.
Another object of the invention is to reduce manual radiography test method.

A still another object of the invention is to improve safety in handling of short length welded tubes during RTR tests.
SUMMARY OF THE INVENTION
The present invention describes an apparatus for performing a real time radiographic test on various welded tubes. According to the invention, outer diameter of the short length welded tubes and a plurality of spool pieces are welded together to configure a telescopic adapter. The short length welded tubes are fixed at the end of the telescopic adapter which is rotated throughout 360°. Positioning a weldment of the short length welded tubes at a centre of a X-ray unit using a pinch roller. The short length welded tubes are inspected using the rotating means. Images of the short length welded tubes are recorded, the telescopic adapter with the short length welded tubes is reversed using the pinch roller and the short length welded tubes of various diameter and thickness, are checked of the short length welded tubes of various diameter and thickness, are checked using the telescopic adapter.
In one embodiment, a method of performing a real time radiographic test on a short length tubes is disclosed. The method comprises welding the short length tubes in straight tube butt welding machine and passing it to an apparatus for conducting a real time radiography test. Positioning a conveyor roller system between a STB welding machine and the real time radiography test system and conveying tubes having a length > 5m to real time radiography test. Similar process carried out for checking the welded lengthy tube using a real time radiographic test system. Conveying the welded lengthy tube through a conveyor roller system up to the weldment of the welded lengthy tube. Positioning the welded lengthy tube at the centre of the X-ray unit by a pinch roller. Setting the X-ray unit to ON position wherein a rotation means is

provided inside the real time radiographic test system which rotates the welded lengthy tube and inspecting the welded lengthy tube throughout 360°using the rotating means.
In one embodiment the short length tubes are welded and using a telescopic adapter which is configured to hold the various outer diameter tubes for checking in the real time radiographic test system. In a preferred embodiment for configuring the telescopic adapter, spool pieces of various diameter are collected from scrap material.
In one embodiment in the real time radiographic system conveying the short length welded tubes in straight tube butt welding machine and then to the real time radiography test system. In a preferred embodiment positioning a conveyor roller system between a STB welding machine and the real time radiography test system. The short length welded tubes having a length > 5m is conveyed to the real time radiography test system. In a preferred embodiment the short length welded tubes is of various diameter which is checked by the telescopic adapter.
In one embodiment a total length of the telescopic adapter is above 5m and the telescopic adapter used to check various thickness of the short length welded tubes. The distance between the two rotation means is lesser than the short length welded tubes.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 shows a overall schematic diagram of a conveyor system to convey the welded tubes from a STB welding machine to a radiographic test system in an embodiment of the present invention.

FIG. 2a shows the overall schematic diagram showing a checking of a full length welded tube in the real time radiographic test system in an embodiment of the present invention.
FIG. 2b shows the overall schematic diagram showing the checking of a short length welded tube in the real time radiographic test system in an embodiment of the present invention.
FIG. 2c shows the overall schematic diagram showing the checking of a short length welded tube in the real time radiographic test system with a telescopic adapter in an embodiment of the present invention.
FIG.3 shows the checking of Ø63.5mm tube with 76.1mm diameter telescopic adapter with handling tube of 5m.
FIG.4 shows the checking of 54mm diameter tube with 63.5mm diameter spool piece +Ø76.1mm telescopic adapter with handling tube of 5m.
FIG.5 shows the checking of Ø44.5mm tube with Ø54+Ø63.5mm spool piece+Ø76.1mm telescopic adapter with handling tube of 5m.
FIG.6 shows the checking of Ø33.1mm tube with Ø44.5+Ø54+Ø63.5mm spool piece+Ø76.1mm telescopic adapter with handling tube of 5m.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION
FIG. 1 shows a overall schematic diagram of a conveyor system to convey the welded tubes from a STB welding machine (02) to a radiographic test system (04) in an embodiment of the present invention. In a preferred embodiment the short length tubes are welded in straight tube butt welding machine (02) and then transfer to the real time radiographic system (04). The conveyor roller system (03) is positioned between the STB welding machine (02) and the real time radiography test system (04) and the short length tubes are converted to a short length welded tube (01). For example: tubes having a length of higher than 5m are conveyed to the real time radiography test system (04).
FIG. 2a shows the overall schematic diagram showing a checking of a full length welded tube in the real time radiographic test system (04) in an embodiment of the present invention. The real time radiographic system (04) is used for checking a welded lengthy tube (06). The welded lengthy tube (06) is conveyed through conveyor roller system (03) up to the weldment. The welded lengthy tube (06) is positioned at the centre of the X-ray unit (07) by using a pinch roller (05). After X-ray unit (07) is set to ON position, a rotation means (08) is configured inside the real time radiographic system (04) which is used to rotate the welded lengthy tube (06). The lengthy welded tube (06) could be checked throughout 360° by using the rotating means(08).
FIG. 2b shows the overall schematic diagram showing the checking of a short length welded tube (01) in the real time radiographic test system (04) in an embodiment of the present invention. The distance between the two rotation means (08) is lesser than the short length welded tubes

(01) for proper checking. The short length welded tube (01) is positioned properly for checking in the real time radiographic test system (04). The short length welded tube (01) is checked in the X-ray unit (07) and positioned properly for rotation. The short length welded tube (01) is conveyed through conveyor roller system (03) up to the weldment. The short length welded tube (01) is positioned at the centre of the X-ray unit (07) by using the pinch roller (05) based on the distance measurement. Using the real time radiographic test system (04) the short length welded tube (01) is checked without additional attachment.
FIG. 2c shows the overall schematic diagram showing the checking of a short length welded tube (01) in the real time radiographic test system (04) with a telescopic adapter (14) in an embodiment of the present invention. The checking of the short length welded tube (01) is done by using a telescopic adapter (14). In a preferred embodiment the telescopic adapter (14) is used for checking various diameter, thickness of the short length welded tube (01). In one embodiment the total length of the telescopic adapter (14) is above 5meter. Positioning the weldment of the short length welded tube (01) to the centre of the X-ray unit (07), by using the pinch roller (05). Rotation means (08) could be used to rotate the short length welded tube (01) throughout 360° for checking any defect in the weldment.
FIG.3 shows the checking of Ø63.5mm tube with 76.1mm diameter telescopic adapter (14) with handling tube of 5m. In a preferred embodiment the short length welded tube (01) of 63.5mm diameter is checked by performing the following steps. Step 1: Taking a tube of Ø76.1mm X 4mm thickness and a length 5000mm. Step 2: A tube of Ø76.1X4mm thickness is selected based on lower weight and easily

handled by using the telescopic adapter (14). Step 3: Another tube I.e (spool piece) (10) of Ø76.1mm X 6.3mm thickness and the tube for a length of 225 mm is cut. Step 4: Then taper turning of inner bore diameter from 64mm to 63.5mm to a length of 75mm is done. Step 5: Then the above said spool piece (10) is welded with 5000mm length tube (09). Step 6: Now this telescopic adapter (14) is used for checking the short length welded job (1A) of Ø63.5mm X various thickness.
FIG.4 shows the checking of 54mm diameter tube with 63.5mm diameter spool piece +Ø76.1mm telescopic adapter (14) with handling tube of 5m. In a preferred embodiment checking a welded tube (1B) preferably short length of Ø54mm is taken. The checking is done by performing the following steps: step 1: A tube (11) of Ø63.5mm X 7.1mm thickness and 225mm length is taken. Step 2: A taper turning at inner bore diameter from 54.5mm to 54mm to a length of 75mm is one. Step 3: A new spool piece (11) is ready to fit inside the Ø76.1mm diameter of previous spool piece (10). Step 4: The Ø76.1mm is welded with Ø76.1X4mm previous 5000mm length tube (09). Step 5: Then this total fixed telescopic adapter (14) could be used for checking the short length welded job (1B) of Ø54mm X various thickness.
FIG.5 shows the checking of Ø44.5mm tube with Ø54+Ø63.5mm spool piece+Ø76.1mm telescopic adapter (14) with handling tube of 5m. In a preferred embodiment checking a welded tube (1C) preferably short length of Ø44.5mm is taken. The checking is done by performing the following steps: step 1: Taking a tube (11) of Ø54mm X 5mm thickness and 225mm length is taken. Step 2: A taper turning at inner bore diameter from 45mm to 44.5mm to a length of 75mm is done. Step 3: New spool piece (12) is ready to fit inside the Ø63.5mm diameter the previous formed spool piece

(11). Step 4: The Ø63.5mm spool piece (11) is already fixed in Ø76.1mm spool piece (10). Step 5: The Ø76.1mm is welded already with Ø76.1X4mm tube (09). Step 6: Then this total fixed telescopic adapter (14) could be used for checking the short length welded job (1C) of Ø44.5mm X various thickness.
FIG.6 shows the checking of Ø33.1mm tube with Ø44.5+Ø54+Ø63.5mm spool piece+Ø76.1mm telescopic adapter (14) with handling tube of 5m. In a preferred embodiment checking a welded tube (1D) preferably short length of Ø33.1mm is taken. The checking is done by performing the following steps: Step 1: Taking a tube (13) of Ø44.5mm X 6mm thickness and 225mm length is taken. Step 2: A taper turning at inner bore diameter from 33.6mm to 33.1mm to a length of 75mm is done. Step 3: Now a spool piece (13) is ready to fit inside the Ø54mm diameter spool piece (12). Step 4: The Ø54mm spool piece (12) is already fixed in Ø63.5mm spool piece (11). Step 5: The Ø63.5mm spool piece (11) is already fixed in Ø76.1mm spool piece (10). Step 6: The Ø76.1mm is welded already with Ø76.1X4mm tube (9). Step 7: Then this total telescopic adapter (14) could be used for checking the short length welded job (1D) of Ø33.1mm X various thickness.
In one embodiment the real time radiographic system (04) for performing a real time radiographic test on a short length welded tubes (01), comprising the steps of: Attaching an outer diameter of the short length welded tubes (01) and a plurality of spool pieces welded together to configure a telescopic adapter (14). Fixing the short length welded tubes (01) at the end of the telescopic adapter (14). Positioning a weldment of the short length welded tubes (01) at a centre of a X-ray unit (07) using a pinch roller (05). Inspecting the short length welded tubes (01) using the rotating means (08), wherein the telescopic adapter (14) rotated throughout 360°. Recording an images of the short length welded tubes (01) wherein

reversing the telescopic adapter (14) with the short length welded tubes (01) using the pinch roller (05) and checking various diameter and thickness of the short length welded tubes (01) using the telescopic adapter (14).
In one embodiment the real time radiographic system (04) for performing a real time radiographic test on a welded lengthy tube (06), comprising the steps of: checking the welded lengthy tube (06) using a real time radiographic test system (04). conveying the welded lengthy tube (06) through a conveyor roller system (03) up to the weldment of the welded lengthy tube (06). positioning the welded lengthy tube (06) at the centre of the X-ray unit (07) by a pinch roller (05). setting the X-ray unit (07) to ON position. Configuring a rotation means (08) inside the real time radiographic test system (04) which rotates the welded lengthy tube (06). inspecting the welded lengthy tube (06) throughout 360°using the rotating means (08) and checking various diameter and thickness of the welded lengthy tube (06) by using the telescopic adapter (14).
In one embodiment the short length welded tubes (01) having a length > 5m is conveyed to the real time radiography test system (04). In a preferred embodiment the short length welded tubes (01) is of various diameter which is checked by the telescopic adapter (14). In a preferred embodiment the total length of the telescopic adapter (14) is above 5m and the telescopic adapter (14) used to check various thickness of the short length welded tubes (01). The distance between the two rotation means (08) is lesser than the short length welded tubes (01). The short length welded tubes (01) varying diameter ranges from 33.1mm to 63.5mm outside diameter.

In one embodiment the short length tube is moved to real time radiographic test system (04). According to the outer diameter of the welded tube, the spool pieces attached with the telescopic adapter (14). Then the short length welded tube (01) is fixed at the end of the telescopic adapter (14). By using the pinch roller (05), the weldment of the short length welded tube (01) is positioned at the centre of the X-ray unit (07). After positioning the weldment, the short length welded tube (01) is ready for test and X-ray unit (7) is started. By using the rotating means (8), the telescopic adapter (14) could be rotated throughout 360° for checking the short length welded tube (1) for defects. After checking, images are recorded and the telescopic adapter (14) with the short length welded tube (1) could be taken reverse by using the pinch roller (5). Now the short length welded tube (1) is removed from the telescopic adapter (14) and another telescopic adapter (14) is ready for further processes. To check weldment of short length tubes having various diameter with various thickness is done by using this telescopic adapter (14).
In one embodiment the short length tubes welded joints are handled by the telescopic adapter (14). This telescopic adapter (14) designed to hold the various outer diameter tubes for checking the RTR test. For making this telescopic adapter (14), spool pieces of various diameter are collected from scrap material.
In one embodiment the total fixed telescopic adapter (14) of all the above spool pieces is looking similar to a telescopic equipment. By using the telescopic adapter (14), various outer diameter of short length job in RTR (real time radiographic) test in very safe is checked with a less time delay. In a preferred embodiment any jobs ( short length, lengthy welded tube) having a length varying from 400mm to 2500mm could use this telescopic adapter (14) for RTR test.

WE CLAIM:
1. A method for performing a real time radiographic test on short length
welded tubes (01), comprising the steps of:
- joining a plurality of spool pieces together to configure a telescopic adapter (14);
fixing a short length welded tube (01) at the end of the telescopic adapter (14);
positioning a weldment of the short length welded tube (01) at a centre of a X-ray unit (07) using a pinch roller (05);
inspecting the short length welded tubes (01) using the rotating means (08), wherein the telescopic adapter (14) is rotated throughout 360°; recording an images of the short length welded tubes (01); reversing the telescopic adapter (14) with the short length welded tubes (01) using the pinch roller (05); and
checking various diameter and thickness of the short length welded tubes (01) using the telescopic adapter (14).
2. The method as claimed in Claim 1, wherein the short length welded tubes (01) are conveyed into a straight tube butt welding machine (02) and then transferred into a real time radiography test (RTR) system (04).
3. The method as claimed in Claim 2, wherein the step of conveying comprises positioning a conveyor roller system (03) between a STB welding machine (02) and the real time radiography test system (04).
4. The method as claimed in Claim 1,wherein the short length welded tubes (01) having a length > 5m.

5. The method as claimed in Claim 1, wherein the short length welded tubes (01) are of various diameter.
6. The method as claimed in Claim 1, wherein a total length of the telescopic adapter (14) is above 5m.
7. The method as claimed in Claim 1, wherein the telescopic adapter (14) used to check various thickness of the short length welded tubes (01).
8. The method as claimed in Claim 1, wherein the distance between the two rotation means (08) is lesser than the length of the short length welded tubes (01).
9. The method as claimed in Claim 1, wherein the outside diameter of the short length welded tubes (01) varying from 33.1mm to 63.5mm.
10. A method for performing a real time radiographic test on a long welded tube (06), comprising the steps of:
checking the welded tube (06) using a real time radiographic test system
(04);
conveying the welded long tube (06) through a conveyor roller system (03)
up to the weldment of the welded long tube (06);
positioning the welded long tube (06) at the centre of the X-ray unit (07) by
a pinch roller (05);
setting the X-ray unit (07) to ON position;
configuring a rotation means (08) inside the real time radiographic test
system (04) which rotates the welded long tube (06);

inspecting the welded long tube (06) throughout 360°using the rotating means (08); and
checking various diameter and thickness of the welded lengthy tube (06) using a telescopic adapter (14).