fixing of orifices in bottom ring header
DESCRIPTION
THIS PRESENTATION IS OF BOILERS WHICH ARE ABOVE 500 MW AND WHOSE DOWN COMERS ARE PRESENT ONLY ON THE FRONT SIDE. THE INSIDE PART OF A RING HEADER IS ALWAYS A MYSTERY TO THE OUTSIDERS.IN THESE SLIDES SEE HOW ARE TUBES PRESENT INSIDE THE HEADER WHICH IS RARE TO SEE FOR ANYONE EVEN THOUGH HE IS WORKING IN A BOILER OR A POWER PLANT.TRANSCRIPT
FIXING OF ORIFICES IN BOTTOM RING HEADER
P.Harish BabuA.E (Mechanical)
H.N.P.C.L, Palavalasa,VISAKHAPATNAM.
Mobile :8106890404
Fixing of Orifices in Bottom Ring Header
Introduction For uniform flow of water to all sides
of the ring header we use orifices in the bottom ring header.As the down comers are positioned in the front side of the Boiler only that side of the ring header may receive more amount of water leaving other tubes to starve. So orifices are used.
Fixing of Orifices in Bottom Ring Header
No of tubes on each side in our ring header
LHS - 212 RHS - 212 FRONT SIDE - 319 REAR SIDE - 319 TOTAL -1062
Fixing of Orifices in Bottom Ring Header
Parts required for fixing of orifices in the ring header
Tubes with protruding studs. Orifice plates with holes matching
the studs Marman couplings with nut and bolt.
Fixing of Orifices in Bottom Ring Header
Procedure to fix Marman Couplings
All the tubes in the ring header are housed inside the perforated trays and these perforated trays are bolted to the studs protruding from the inner wall of the ring header.
In order to fix Marman couplings these trays have to be removed , stored with proper care and then re-fix as usual when the fixing of Marman couplings is completed.
Original shape of the tube for fixing the orifice. The 3 studs projecting out
are different for different DU Numbers.
Orifice plate with
holes.
Nut and bolt
Marman
coupling
Stud protruding from inner wall of
the header to accommodate
perforated trays
Fixed Marman couplings inside the ring header
Perfectly fixed Marman coupling Nut and bolt are tight.
3 studs are clearly seen out protruding after fixing of orifice
plate.Uniform gap is seen all over .
Checking of tightness of Marman coupling.
Inside the bottom ring
header
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