Emerson 2468CD Manuel D’Utilisation

Hydrastep Pressure Parts 

Fault Repair and Commissioning 

 

With any steam/water detection gauge, a partial blockage or leak within the pressurised 
system may result in incorrect water level indication.  The Hydrastep water column design is 
such that density errors in water level indication (due to the water temperature in the column 
being lower than the water temperature in the boiler drum) are minimised for the 
temperatures and pressures specified.  This is achieved by stimulating condensate flow in 
the upper part of the column by omitting lagging on the column steam pipe.  The flow of 
condensate maintains the temperature of the water column close to that of the boiler drum. 

Caution:  If a serious “blow” occurs, immediate attention is required.  Ensure that the 

column or manifold is VALVED OFF AS SOON AS POSSIBLE otherwise any 
resulting electrode seat erosion may require the removal of the column or 
manifold for re-machining of the ports.  Site machining of the water column is 
possible and satisfactory results can usually be obtained (for small leak damage). 

 

a) 

Ensure that tripping, where fitted, is disabled and that the operators are briefed to 
expect erroneous indications or alarms. 

b) 

Ensure that you know the valve positions and other procedures BEFORE working on the 
water column. 

c) 

Allow the water column to cool before changing electrodes and check for signs of steam 
at the drain to ensure complete isolation. 

d) 

Wear industrial gloves to change electrodes. 

e) 

On Low-level Tripping Schemes, either electro-mechanical interlocks or recognised 
procedures MUST be applied to ensure that draining the column does not cause a 
spurious trip. 

f) 

Refit the electrode covers before pressurising the column. 

g) 

It is strongly recommended that a ‘HOT’ notice is attached to the water column in a 
prominent position. 

h) 

Ensure that all safe working practices for the media and processes concerned are 
followed during the installation and maintenance of the equipment. 

i) 

If the equipment is likely to come into contact with aggressive substances, it is the 
responsibility of the user to take suitable precautions that prevent it from being 
adversely affected, thus ensuring that the type of protection both mechanical and 
electrical are not compromised. 

j) 

The equipment, both mechanical and electrical, must not be used as a support for other 
equipment or personnel. 

k) 

Both mechanical and electrical content of the system must be protected from impact. 

l) 

The Hydrastep installation is not protected by integral over pressure relief valves. Where 
fitted directly to a boiler installation, ensure the Hydrastep water column and associated 
pipework are protected from over pressurisation by the boiler safety valves.