Spirax Sarco - Catalogo Agosto 2017

For full details see the Installation and Maintenance Instructions that are supplied with the product.

Installation note:

Desuperheaters may be installed either horizontally or vertically with the steam flowing upwards.

Spirax Sarco strongly advises against installations in which the steam flow is vertically downwards.

In the case of a horizontal installation the cooling water connection should ideally point downstream, as this gives the best orientation

for drainage of fluids in a shutdown situation. Other orientations are acceptable for satisfactory operation, but drainage is not as effective.

In a vertical installation we recommend that, the cooling water pipework should be brought to the desuperheater from below the

corresponding connections on the desuperheater. This will provide the best layout for drainage of fluids on shutdown.

The VAD must be sited in location on the pipeline that offers a stable flow - An unstable flow will affect the mixing efficiency of the VAD.

VAD

PN9000 series actuator

Position of nozzles

Temperature sensor

Installation depends on the application

Steam

flow

6 m

A typical installation illustrating a VAD variable area desuperheater in conjunction with a PN9000 series actuator

The temperature sensor should be located a minimum distance of calculated on the sizing sheet (and typically more them 12m) after

the VAD, however for optimum temperature control it is recommended that it be installed at the point of use.

A minimum length of 5 metres should be present before a pipe elbow. A thermal sleeve is recommended to protect the elbow from

corrosion and erosion.

The steam pipeline should be of at least DN150. At steam line sizes up to and including 20" NB, we recommend the thermal sleeve is

manufactured from pipe which is one size smaller than the steam line. Above 20" NB steam line size, we recommend the thermal sleeve

is two sizes smaller.

Pipe size should ensure a minimum 5m/s velocity in each flowrate, in case of lower value please contact Spirax Sarco

Water must be supplied with more than 3 bar differential pressure to the steam.

Disposal

The product is recyclable. No ecological hazard is anticipated with disposal of this product, providing due care is taken.

The location of the VAD in the pipeline must be such that it offers a stabilised flow. Unstabilised flow will affect the mixing efficiency.

The VAD must be sited in location on the pipeline that offers a stable flow - Unstabilised flow will affect the mixing efficiency.

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TI-P451-01 CH Issue 3