Installation Procedures

Hydrastep Pressure Parts

The water connection to the water column must be fully insulated by lagging. The steam connection must also be lagged, but a minimum length of 0.5 metre of the steam leg must be left unlagged where the steam leg joins the water column (see Figure 2.2).

Lagging the water column will reduce the density error, provided that 0.5 metre minimum of the steam leg is left unlagged.

If errors in the water level indication are observed, it may be necessary to lag the water column, either up to NWL or for it’s full length, depending on the ambient conditions prevailing at the site. Suitable lagging, part number 450601450, is available from Mobrey.

When the installation of the water column has been completed, precautions must be taken to protect it against damage during the installation of adjacent plant and pipework.

Note: Particular attention must be paid to the protection of the electrode sealing surfaces in the column against foreign bodies or weathering. For this purpose the following sealing plugs should be fitted as appropriate:

L.P. Sealing Plug

Part No. 24569A

Series 3 Sealing Plug

Part No. 450600880

Caution: If there is any possibility of the ambient temperature at drum level falling below zero °C for any period when the boiler is not operational, it is ESSENTIAL that the water column is isolated, drained and vented to prevent ice-expansion damage to the electrodes in the column. Ice-expansion damage can also affect adjacent valves.

For instructions regarding the assembly of electrodes in the water column, see Chapter 3, sub-section 3.1.4 (low pressure electrodes) and 3.1.5 (high pressure electrodes).

2.4INSPECTION OF MECHANICAL INSTALLATION WORK

When the mechanical installation work has been completed, the site surveillance staff may be required to inspect the work and the equipment, such as the installation of the electronics unit and the installation of the water column, checking particularly the level relative to the drum, before releasing it for electrical work and cabling.

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Emerson 2468CB, 2468CD manual 2.4INSPECTION OF MECHANICAL INSTALLATION WORK