Page 22 - Alfagomma-Industrial-Rubber-Catalog-Revised-1-28-10

BECAUSE WE CONTINUALLY EXAMINE WAYS TO IMPROVE OUR PRODUCTS, WE RESERVE THE RIGHT TO ALTER SPECIFICATIONS WITHOUT PRIOR NOTICE.
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SteamSteam Hose Safety Facts
Handling steam is a very hazardous situation. Using care and
some safety precautions can minimize or eliminate personal or
property damage.
SELECTING AND USING STEAM HOSE
1. Make sure steam hose is identifed as a steam hose. It
should be branded as such, stating working pressure and
temperature rating.
2. Make sure working pressure and temperature is not
exceeded.
3. Do not allow hose to remain under pressure when not in
use.
4. Avoid excess bending or fexing of hose near the coupling.
Straight line operation is preferred. If bends are necessary as
part of operation, spring guards may help.
5. Be sure to use recommended steam hose couplings and
clamps on hose.
MAINTENANCE OF STEAM HOSE
1. Periodic inspection of hose should include looking for cover
blisters and lumps.
2. Check for kinked areas that could damage hose.
3. Drain hose after each use to avoid tube damage before hose
is put back in operation, to avoid “popcorning” of the tube.
4. Check tightness of clamp bolts after each use.
5. Check to see if clamp halves are touching. If they are,
recouple hose with smaller clamps to insure proper tightness
or grip around hose.
6. Do not store hose over hooks.
7. Steam hose lying on metal racks or installed around steel
piping will dry out the hose, causing tube and cover cracking.
8. For service in sub-zero applications, use only T331
Chlorobutyl hose.
The charts represent the three forms of water when subjected
to heat and pressure. Use only hoses specifcally designed for
the application.
Reprint from RMA lP-l 1-1 1987
STEAM HOSE CHART
SATURATED STEAM
Gauge Temperature
Pressure of Saturated
(PSI) Steam (°F)
10 239
25 267
50 298
75 320
100 338
125 353
150 366
175 377
200 388
225 397
250 406
TEMPERATURE OF SATURATED STEAM
Gauge Temp- Gauge Temp-
Pressure erature Pressure erature
lbl/ Kgf/ Atm Bar °C °F lbl/ Kgl/ Atm Bar °C °F
m2cm2 m2cm2
25 1.76 1.70 1.73 130 267 120 8.44 8.16 8.28 177 350
30 2.11 2.04 2.07 134 274 140 9.84 9.52 9.66 182 361
35 2.46 2.38 2.42 138 281 160 11.25 10.88 11.04 188 371
40 2.81 2.72 2.76 141 287 180 12.65 12.24 12.42 193 379
45 3.16 3.06 3.11 144 292 200 14.06 13.60 13.80 198 388
50 3.52 3.40 3.45 148 298 225 15.82 15.30 15.53 203 397
60 4.22 4.08 4.14 153 307 250 17.58 17.00 17.25 208 406
70 4.92 4.76 4.83 158 316 275 19.33 18.70 18.98 212 414
80 5.62 5.44 5.52 162 324 300 21.09 20.40 20.70 216 422
90 6.32 6.12 6.21 166 330 325 22.85 22.10 22.43 221 429
100 7.03 6.80 6.90 170 338 350 24.61 23.80 24.15 225 437
CORROSIVE STEAM
When the water used to generate steam contains dissolved air,
oxygen or carbon dioxide, these gases end up as contaminants
in the steam. At the high temperatures of steam both oxygen
and carbon dioxide are extremely corrosive.
Carbon dioxide is acidic and therefore attacks metals, whereas
the oxygen corrodes metals and oxidizes rubbers. Corrosion of
metals in the presence of both oxygen and acids is forty times
faster than with either alone. Boiler water is therefore normally
treated not only to remove the “Hardness” which would cause
“furring” of the boiler but also to remove dissolved oxygen and
carbon dioxide and to ensure that the steam is not only not
acidic but even slightly alkaline. Boiler water treatment is a
specialized subject beyond the scope of this booklet but
correct steam generation is important as we shall see in the
next section.
DETERIORATION OF STEAM HOSE
Like all rubber products steam hoses have a fnite life and are
subject to gradual deterioration with use. However, it some-
times happens that hoses which have been giving a good life
suddenly start failing without apparent reason. In such cases, it
is often a change in the steam conditions causing a rapid
acceleration of the normal failure mode. It is therefore useful to
consider how long steam hoses normally last and thus how the
condition of the steam affects hose life.
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