FIELD OF THE INVENTION:
The invention relates to welding of nozzles in general and to welding of kicker stage nozzles on
discharge cover of boiler feed pumps of turbine-generator (T-G) units in particular.
BACKGROUND AND PRIOR ART:
Boiler Feed Pump is one of the important auxiliary equipment in Turbine Generator (T-G)
package of a thermal power station. The function of a boiler feed Pump is to feed high pressure,
high temperature feed water to the boiler drum for steam generation. In order to maintain the
required temperature control in the boiler super heater, feed water spray is taken at a very high
pressure from the kicker stage nozzles of boiler feed Pump. The number and size of these kicker
stage nozzles is dependent on the attemperation flow requirement of the boiler. It is required to
maintain accurate location and tightening of the kicker stage flange connections to avoid leakage
and flashing.
It follows therefore, that the performance of the boiler and its efficiency is dependent on proper
attemperation flow, which in turn depends on accurate location, both radial and angular, of the
kicker stage nozzles. These nozzles are fixed on to the discharge cover of the boiler feed pump
by welding.
In the prior art, the location of the nozzles on the discharge cover was carried out manually. In
the manual process, nozzles are located on discharge cover, holding the job vertically in a vice.
Angular location of the nozzle is very difficult and tedious in the manual method. A lot of precious
time is wasted at the time of erection of the boiler feed pump.
Moreover, usually a plurality of nozzles, typically four nozzles are fixed on the discharge cover of
every boiler feed pump of 500 MW TG set for example. For each such nozzle, matching of PCD
holes with respect to the counter flanges of high temperature pipelines is to be undertaken at
site. This too is a painstaking and laborious activity.
As these activities are undertaken manually at site, where there is great pressure for completion
in minimum time, scope of error is large.

(2)
The manual process of the prior art involves deployment of considerable workforce for long
periods of time, and is also at times hazardous for the workers.
The holding fixture in accordance with the invention seeks to overcome these drawbacks of the
prior art.
OB3ICTS OF THE INVENTION:-
One object of the invention is to provide a fixture for accurate location of the nozzles.
Another object of the invention is to reduce the scope of error in location of the nozzles on the
discharge cover.
A further object of the invention is to reduce the time taken for locating the nozzles on the
discharge cover.
Yet another object of the invention is to reduce the manpower required to undertake this activity.
DESCRIPTION OF THE INVENTION:-
The invention will be described with the help of the accompanying drawings. The detailed
description of the invention following herebelow is made with an exemplary embodiment of
discharge cover plate and kicker stage nozzles of boiler feed pump of a 500 MW T-G unit, but it is
clarified that the invention is not restricted to the exemplary embodiment only. There can be
several other embodiments covering other ratings of boiler feed pumps, all of which are deemed
covered by this description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Fig.l shows the top view of the holding fixture in accordance with the invention with kicker stage
nozzles and discharge cover in position.
Fig.2 shows the top view of a discharge cover with 4 kicker stage nozzles.
Fig.3 shows a photographic view of the fixture shown in Fig.l.
Fig.4 shows a photographic view of the fixture with a discharge cover and nozzles positioned
thereon for welding.
Fig.5 shows a photographic view of a discharge cover with nozzles welded on to it with help of
the fixture.

(3)
The holding fixture (1.0) in accordance with the invention comprises a circular steel plate (1.1) of
suitable thickness and diameter. In the exemplary embodiment, the thickness lies between 70
and 90 mm and the diameter between 2.5 to 3.2 meters. The discharge cover (2.0) of a 500 MW
boiler feed pump has 4 kicker nozzles (2.1) two of which are at 10 degrees and the other two at
50 degrees from the horizontal central line of the discharge cover (2.0) Corresponding to these
angular positions, weld neck flanges (1.2) are mounted on the circular plate (1.1).
The neck flanges (1.2) are carefully located exactly in the positions as needed for the positions of
the kicker stage nozzles and are fixed on to the circular plate (1.1). They are provided with tubes
(1.3) for support, which are welded to the back face of the neck flange (1.2) and to the circular
plate (1.1).
The holding fixture (1.0) is provided with a hollow pipe (1.4) which is welded at the center of
the fixture on the circular plate (1.1). The outer diameter of this hollow pipe, mounted coaxially
with the circular plate of the fixture, matches the internal diameter of the discharge cover (2.0).
This pipe ensures the central alignment of the discharge cover when it is placed on the holding
fixture. The fixture thus made is shown in Fig.3.
The holding fixture (1.0) is placed horizontally on the shop floor. The discharge cover (2.0) is
then placed on the holding fixture centrally, hollow pipe (1.4) being used as the center-location
guide. The discharge cover is positioned around this pipe. The kicker nozzles (2.1) are then
placed between the neck flanges (1.2) and the discharge cover (2.0) and aligned with the neck
flanges (1.2). This is depicted in Fig.4 photographically.
As the neck flanges (1.2) have been pre-located accurately both radially and angularly, the kicker
nozzles are automatically located at their correct positions for welding. The welding is then
carried out to fix the nozzles on to the discharge cover. Fig.5 shows a photographic view of a
discharge cover which has been fitted with kicker nozzles with the help of the holding fixture in
accordance with the invention.
It is clear from the above that the invention overcomes the difficult and tedious operation of
manually locating and welding the kicker nozzles in the vertical position, as practiced in the prior

(4)
WE CLAIM:
1. A holding fixture (1.0) for precise radial and angular location of kicker stage nozzles
comprising a circular steel plate (1.1) a plurality of weld neck flanges (1.2) carefully
located and fixed on the circular plate (1.1), neck flanges being supported by tubes (1.3)
which are welded to the back of the neck flanges and also to the circular plate (1.1), the
circular plate being provided with a hollow pipe (1.4) located coaxially and welded to the
circular plate (1.1), characterized in that a plurality of kicker stage nozzles (2.1), when
placed between the neck flanges (1.2) and the discharge cover (2.0) and aligned with
the flanges are automatically positioned in their exact locations for welding to the
discharge cover.
2. A holding fixture (1.0) as claimed in claim 1, wherein the thickness of the circular plate
lies between 70 mm and 90 mm and the diameter lies between 2.5 m and 3.2 m.
3. A holding fixture (1.0) as claimed in claim 1, wherein the kicker stage nozzles (2.1) are
welded to the discharge cover (2.0) in the horizontal position.
4. A holding fixture (1.0) as claimed in claim 1, wherein the kicker stage nozzles (2.1) are
located at 10 degrees and 50 degrees from the horizontal central line of the discharge
cover (2.0).

1. A holding fixture (1.0) for precise radial and angular location of kicker stage nozzles
comprising a circular steel plate (1.1) a plurality of weld neck flanges (1.2) carefully
located and fixed on the circular plate (1.1), neck flanges being supported by tubes (1.3)
which are welded to the back of the neck flanges and also to the circular plate (1.1), the
circular plate being provided with a hollow pipe (1.4) located coaxially and welded to the
circular plate (1.1), characterized in that a plurality of kicker stage nozzles (2.1), when
placed between the neck flanges (1.2) and the discharge cover (2.0) and aligned with
the flanges are automatically positioned in their exact locations for welding to the
discharge cover.