INSULATION COVER OF STEAM TRAP

REVETEMENT ISOLANT POUR DESHUMIDIFICATEUR DE VAPEUR

English Abstract

ABSTRACT OF THE DISCLOSURE
In a steam trap having an outer casing and pipe
connection portions extending outwardly therefrom, the
trap including an outer covering member extending over the
outer casing and in spaced relation thereto, the covering
member mechanically abutting against the pipe connection
portions, the improvement comprising: fusing the covering
member to the pipe connection portions whereby to positively
join the covering member to the pipe connection portions
and provide a sealed air- and water-proof joint therebetween
and accordingly a sealed space surrounding the steam trap.

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. In a steam trap having an outer casing and pipe
connection portions extending outwardly therefrom, said
trap including an outer covering member extending over
said outer casing and in spaced relation thereto, said
covering member mechanically abutting against said pipe
connection portions, the improvement comprising: fusing
said covering member to said pipe connection portions
whereby to positively join said covering member to said
pipe connection portions and provide a sealed air and
water-proof joint therebetween and accordingly a sealed
space surrounding said steam trap.
2. The improvement, as defined in claim 1, wherein
said fusing of said cover member is by welding to said
pipe connection portions.
3. The improvement, as defined in claim 1, wherein
said fusing of said cover member is by braising said pipe
connection portions.
4. The improvement, as defined in claim 1, wherein
said fusing of said cover member comprises two parts
which are butt-joined together by welding.
5. The improvement, as defined in claim 1, wherein
said fusing of said cover member comprises two parts
which are butt-joined together by braising
6. The improvement, as defined in claim 1, wherein
the spacing between said outer casing and said outer
covering member comprises insulating material.

7. The improvement, as defined in claim 6, wherein
said insulating material comprises ceramic fibre.

Description

~7~;~3~
The present invention relates to improvements in
steam traps, for example, ones which automatically discharge
condensate from steam systems. It more particularly relates
to the jointing construction between the casing of such traps
and the outer covering member therefor, which may comprise
an insulation cover. Such insulation covers have come into
being with the growing tendency to energy conservation,namely
to prevent the steam heat loss from steam traps due to
radiation.
An example of known steam trap is disclosed in the
Japanese Patent Gazette, showing Utility Model Sho 56-12480.
In this example, an outer covering member covers the entire
surface of the trap casing, providing a clearance for
insulation with the trap casing. In such instance, the covering
member only mechanically abuts against the piping connection
part of the trap casing.
A major drawback respectivé the example comprising
the prior art, is that it suffers poor insulation quality.
This is due to the covering member, which may comprise various
materials including ones which can be welded or braised,
mechanically abutting the trap casing, resulting in a gap at
the jointing~portion, i.e., intermediate the pipe connection
portions thereof and the covering member. Such permits flow-
in and out of air and intrusion of water into the aforementioned
clearance for insulation. The flow-in and out of air and
intrusion of water are expedited by expansion and contraction
of air or water in the clearance for insulation space, thus
causing a decreasing insulation effect due to heat dissipation.
It is therefore a prime aim of the present invention
to eliminate the gap between the trap casing and the edge of
the outer covering member.

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In one aspect of the present invention there is
provided in a steam trap having an outer casing and pipe
connection portions extending outwardly therefrom, the trap
i~cluding an outer covering member extending over the outer
casing and in spaced relation thereto, the covering member
mechanically abutting against the pipe connection portions,
the improvement comprising: fusing the covering member to the
pipe connection portions whereby to positively join the covering
member to the pipe connection portions and provide a sealed
air and water-proof joint therebetween and accordingly a sealed
space surrounding the steam trap.
For example, by welding or braising the pipe
connection portions to the outer covering member, the gap
between the casing and the edge of the outer covering member
is completely eliminated. Flow-in and out of air nor
intrusion of water no longer occurs. When sealing the gap,
the sealing material is required to be heat-resistant. Sealing
by welding or braising provides an ideal joint including in
terms of being heat-resistant.
The inven-tion is iilustrated by way of example in
the accompanying drawing wherein
FIGURE 1 is a part sectional view taken through
a steam trap in accordance with the
present invention.
Referring to Figure 1, numeral 1 denotes the
conventional steam trap, the trap having a casing 1' and pipe
connections 2 and 3 extending therefrom. Numerals 4 and 5
denote respectively portions of an outer covering member A.
To facilitate assembly, outer covering member A is thus split
into two segments while arranged to cover the entire outer
surface of trap 1, except for the pipe connections 2 and 3.
Segments or portions 4 and 5 are fitted to trap 1 and welded
together along the central periphery denoted by numeral 8 and

7~ 37
further welded to trap casing 1' at steps comprising pipe
connections 2 and 3 denoted respectively by numerals 6 and 7.
A clearance space 9 is formed between the inner surface
of the cover A and the outer surface of the trap casing 1'.
Clearance space 9 may be filled with insulating material such as
ceramic fibre.
During operation of the steam trap in accordance with
the present invention, no intrusion of water occurs into the
clearance space 9, thus the insulating material therein will
not deteriorate, and the initial good insulation performance
remains in tact.
In the case of conventional prior art devices having
merely a clearance space between the outer covering member and
the trap casing, the radiation heat loss is equivalent to
condensation of 0.16 Kg per hour under the conditions of 5 kg/cm2G
trap inlet steam pressure and 10 mm/hr rain fall. Using the
insulated covering member according to the present invention
with the same steam trap, the heat loss is reduced to 0.11 Kg/hr.
This is simply one example to illustrate the improved efficiency
gained as a result of the present invention.
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Representative Drawing