FIELD OF THE INVENTION:
The invention relates to a device for edge preparation of the pipes used in the high pressure boilers for power generation. More particularly the invention relates to a device of damping the pipe in the special purpose machine for the edge preparation.
BACKGROUND OF THE INVENTION:
Normally the edge preparation is carried out in the special purpose machine in the following manner. Referring to fig (1), the semicircular clamps(1) are used in either side of the machine clamping jaws(2) to held the work piece(5) having outside diameter ranging from 88.9mm to 219mm with the thickness ranging from 5.5mm to 30mm.The material is of carbon steel and alloy steel of P22,P9i grade. For the edge preparation, each time the circular clamps are to be replaced accordingly to the diameter of the pipe to be edge prepared.
The semicircular clamps weighing in the range of 30kg to 40 kg depending upon the diameter of the pipe to be edge prepared. So there is a dependency on crane involved in fixing the semicircular clamps on the machine jaws and a good amount of setting time that affects the production. The safety is also another factor to be considered while fixing the clamp.
Hence there was a need to find out an alternate method involving a suitable device for fixing the pipes in the same machine to improve productivity.

A primary object of the invention was to develop a device for clamping during edge preparation of riser pipes used in boilers for steam generation that can act as a universal clamp for multiple size of pipes avoiding frequent use of crane, saving lot of time during setting and easy to operate,
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
FIGURE 1: Shows the pipe and machine with semicircular clamp in position.
FIGURE 2: Shows the developed V clamp fitted with semicircular clamp by means by Allen bolts.
FIGURE 3: Shows the full machine with V clamp
FIGURE 4: Shows the V damp with serration made there on for better grip.
DETAILED DESCRIPTION OF THE PREFERED EMBODIMENT OF THE INVENTION:
Accordingly, the maximum diameter of the pipe to be edge prepared in the machine 219 mm, hence one special V damp (3) which has an included angle of 120 degree was machined which can hold the pipe diameter of 88.9 to 219 mm to suit the semicircular clamps (1) which is already fastened on the jaws (2) of the machine. The developed V clamp (3) outer surface is made suitable to match the entire surface contact of the semicircular clamps of size 0 219 mm. 6 Nos. of V clamps (3) is made with serrations as shown in the figure 3 for the better gripping of the pipe clamp edge preparation. Internal thread of M12 is made at the center of the V clamp (3) so as to fix this clamp (3) with semicircular clamp which is drilled and threaded with M12 tapping, Allen bolt M12 (4) is used to fix the V clamp (3) with the semicircular clamp (1). Now the machine is capable of fixing any size diameter of the pipe ranging from 88.9 to 219 mm and there is no need for dismantling the whole setup for edge preparation. Hence there is substantial saving in man power for this operation.

We claim
A device for damping of riser pipe during edge preparation comprising:-
- a plurality of semicircular clamp body (1) having an inner surface (5) wherein a plurality of V clamps are fixed such that the outer surface (6) of V clamp (3) abut with the circular inner surface (5) of clamp body (1), the said V clamp (3) having inner surfaces in the form of two-inclined planes at an angle of 120° C and serrated surfaces that grip firmly pipes of variable outer diameter, wherein the V damps (3) are fixed to the clamp body (1) with the help of M12 Allen bolt and M12 tapping hole on the clamp body (1).