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

THANK YOU