Emerson HANCOCK Installation, Operation And Maintenance Instructions

HANCOCK CAST STEEL - GATE, GLOBE AND CHECK VALVES

INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS

Before installation these instructions must be fully read and understood

1.2 Inspection

Before carrying out a valve installation, it is
important to determine whether the valve is in
asatisfactory condition.
The following generally applicable procedure
may be helpful in avoiding subsequent valve
problems and should be observed.
a) Carefully unpack the valve and check tags,

identification plates, direction of rotation
of handwheels etc, against bill of material,
specifications, schematics etc.

b) Make a point of noting any special warning
Instructions for DN 50 - 600 (NPS 2 - 24)
ASMEclass 150, 300 and 600 bolted bonnet
caststeel valves.

SAFETY NOTICE

It is essential that a safe system of work
should be adopted before any maintenance
work is done on a valve. The following safety
considerations should be taken in to account
when preparing maintenance instructions.
Before removing valves from a pipework
system or dismantling a valve to carry out
maintenance, it will be necessary to open,
or partially open, the valves and to flush the
system to remove all traces of dangerous
fluidsand pressures.
It is important to recognize the danger
associated with the removal of the stem
packing gland with pressure in the pipework
system and the use of the backseat should not
be regarded as a device permitting repacking
of the stem packing gland whilst the valve
is under pressure as this is recognized as
dangerous practise.

tags or plates attached to or accompanying
the valve, and take any appropriate action.

c) Check the valve for any marking indicating

flow direction. If the flow direction is
indicated, appropriate care should be
exercised to install the valve for proper
flowdirection.

d) As far as is practicable, inspect the valve

interior through the end ports to determine
whether it is reasonably clean, free from
foreign matter and harmful corrosion.
Remove any special packing materials,
such as blocks used to prevent disk
movement during transport and handling,
and anti-corrosion packs. Wipe clean from
preservation coatings, particularly seatings.

e) If practicable, cycle the valve through open

and close. Check guides or seat faces, etc.

f) Immediately prior to valve installation,

check the pipework to which the valve is
tobe fastened for cleanliness and freedom
from foreign materials.

1 GENERAL INSTALLATION INSTRUCTIONS

1.1 General

The installation procedure is a critical stage in
the life of a valve and care should be taken to
avoid damaging the valve.

© 2017 Emerson. All Rights Reserved.Emerson.com/FinalControl VCIOM-02504-EN 19/04

HANCOCK CAST STEEL - GATE, GLOBE AND CHECK VALVES

INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS

1.3 Flanged joint assembly

Pipe flanged joints depend on compressive
deformation of gasket material between the
facing flange surfaces for tight sealing.
In order to obtain satisfactory flange joints,
thefollowing points should be observed.
a) Check the mating flange facings (both valve

and pipework flanges) for correct gasket
contact face, surface finish and condition.

b) Check the bolting for proper size, length

and material. A carbon steel bolt on a high
temperature flange joint can result in early
joint failure.

c) Check the gasket material. For flange joints

using low strength bolting, such as may be
provided for iron flanges, metal gaskets
(flat, grooved, jacketed, corrugated or spiral
wound) should not be used.

d) Check the gaskets for freedom from defects

or damage.

e) Take care to provide good alignment of

the flanges being assembled. Use suitable
lubricants on bolt threads. In assembly,
sequence bolt tightening to make the initial
contact of flanges and gaskets as flat and
parallel as possible. Tighten gradually and
uniformly to avoid the tendency to twist one
flange relative to other.

f) Parallel alignment of flanges is especially

important in the case of the assembly of a
valve in to an existing system. It should be
recognized in such instances that, if the
flanges are not parallel, it will be necessary
to introduce bending to make the flange
joint tight. Simply, forcing the flanges
together with the bolting may bend the pipe,
or it may bend the valve.

g) All bolts shall be tightened in a star

pattern as shown below to ensure uniform
gasketloading.

1.4 Butt weld joint assembly

All welding should comply with the appropriate
pipe system or application code. Welded
joints, properly made, provide a structural
andmetallurgical continuity between the
pipeand the valve body.
Butt welds require full penetration and
thickness at least equal to that of the pipes.
If a pipe of high strength alloy is welded to a
valve with body material of lower mechanical
strength, the weld should taper to a
compensating greater thickness at the valve
end, or the valve should have a matching high
strength welded-on extension.

Particular care is necessary when welding

valves into the line. Considerable distortion,

resulting in line strains, may occur if valves

are not welded into the line with care, where

required, the weld properly stress relieved,

but it is necessary to ensure that such stress

relieving does not result in valve components,

particularly the seatings being subjected to

unacceptable temperatures.

It is recommended that the valves are not

installed in the pipework at points of high

bending moments, as this can adversely

affectthe seating performances.

1.5 Testing and adjustment

Following installation, all valves should

be operated to check that they still

functioncorrectly.

On new pipework systems, system pressure

testing and commissioning follow after

installation when various checks are made.

Valves are usually supplied in the lubricated

condition, but it is recommended that checks

are made to ensure that this is still intact,

particularly after the application of heat

(e.g.welding operation).

A first observation can be made by actuating

the valve through an open-close or

close-opencycle.

It is common practice, after installation of

pipework systems, to clean the system by

blowing with a gas or steam or flushing with

a liquid to remove debris and / or internal

protective films and coatings. It should be

recognized that valve cavities may form a

natural trap in a pipework system and material

not dissolved in or carried out by the flushing

fluid may settle in such cavities and adversely

affect valve operation. Also, abrasive material

carried by a high velocity fluid stream may

cause serious damage to seating surfaces.

Do not subject the valve to pressures/

temperature testing in excess of its

statedlimits.

1

8

4

6

BOLT TORQUING SEQUENCE
1-2-3-4-5-6-7-8

5

3

7

2

2