SPP Pumps Transformer Oil Pumps User Manual
Page 7

Operators Instructions for
Transformer Oil Pumps
Manual No/Rev
W61-001E / 9
Our policy is one of continuous improvement and we reserve the right to alter specifications without giving notice.
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1
Section 3.0
General Description
3.1
Transformer Oil Pumps (Type AT)
SPP Pumps Limited Type AT pumps are ranges of axial (in-line) and
centrifugal end-suction (elbow) oil pumps designed to pump oil within the
cooling circuits of electrical transformers and converters. These may be
static or mobile, e.g. locomotive traction transformers. The casing material
can be either cast iron or lightweight aluminium.
The axial (in-line) pump consists of a pump impeller and driving motor,
mounted on a common shaft, with the transformer oil flowing through the
windings. This eliminates the need for a shaft seal. The oil serves to cool
the motor and lubricate the shaft bearings. Some pump types are also fitted
with an impeller/shaft locking device. Pumps can be mounted vertically or
horizontally, and are both compact and weatherproof.
The centrifugal end suction (elbow) pump has a similar pumpshaft
arrangement except the transformer oil does not flow through the windings.
The motor does, however, remain flooded to provide cooling and lubrication
for the bearings. An end casing is fitted allowing the oil to be drawn in
through the centre of the casing and out through the side. Pumps can be
mounted vertically or horizontally and combined with the elbow arrangement
this gives a wide range of suction/discharge positions.
The pump suction and delivery branches both end in drilled flanges. These
are suitable for bolting directly into the pipework. In some cases the suction
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