| 1.
Q: What is the maximum continuous service pressure of the
aluminum casting on an aluminum jacket?
A: The aluminum casting material of the ControHeat jacket
carries no pressure load. The pressure of the
heating media is contained entirely within the specially fabricated pressure vessel in
each jacket half. The aluminum casting serves
only to distribute heat evenly over the base component.
2. Q: What mechanism prevents leakage of the heating
media being transferred from one jacket half to the
other?
A: Each half of
a ControHeat jacket contains its own specially fabricated pressure chamber. The heating
medium is transferred from one jacket half to the other with an external jumpover.
3.
Q: How much of an air gap is there between the ControHeat jacket and the
component to be heated?
A: Normally
none. Although the ControHeat jacket is cast with a nominal clearance (approximately
1/16’) which allows for mold shrinkage and dimensional tolerances between identical
base items, CSI recommends the use of conventional heat transfer cement with large grains
of graphite to provide a continuous heat circuit between the jacket casting and the base
component.
4.
Q: Do the differentials of the thermal expansion — the steel pressure
vessel in the ControHeat jacket, the aluminum casting material, the heat transfer cement,
and the base component (usually of steel) — cause a drop-off in the heat performance
of a ControHeat jacket in prolonged service?
A: Although there
are differentials of thermal expansion present in a ControHeat jacket system, the effects
are minimal. ControHeat jackets have been in service for many years attaining and
maintaining process temperature above 750F.
5.
Q: Do the different materials of construction of the ControHeat jacket cause
anodic reaction problems?
A: We have
not received a report where anodic reaction has been a problem with a ControHeat jacket.
6.
Q: Are ControHeat jackets used in environments hostile to aluminum casting?
A: Yes. ControHeat
jackets are available with TEE or other coatings for service in halogene-type or other corrosive environments.
However, because most jackets are insulated, they are protected from atmospheric
corrosion.
7.
Q: When the base item is removed from the process for maintenance and replaced
with another item, will the ControHeat jacket fit the new item?
A: Yes, when the
replacement is identical to the first item. No, when the replacement item is not identical
to the first item.
8.
Q: How long will a ControHeat last at continuous rated service?
A: Many jackets have been in continuous service since they were
introduced in 1973; however, CSI has been unable to establish a time-between-failure rate.
As a general rule, the jackets can be expected to outlast the base component and reused
several times.
9.
Q: From whom does CSI obtain the castings for the ControHeat jackets?
A: Controls Southeast operates complete production facilities
(fabrication, patternmaking, and foundry)
for ControHeat jackets. Each jacket is designed, produced and tested in CSI facilities.
10.
Q: What are the types of problems encountered with ControHeat jackets?
A: Most reported problems can be traced to poor communication between
CSI and the customer. For example, the customer may order a ControHeat jacket for standard service (150 psig), while the
actual service conditions may be much higher (such as 450 psig), or, a component
manufacturer may change the exterior design of a component which affects the fit of a
ControHeat jacket. These problems are rare and we are constantly on our toes to circumvent
any misunderstandings about the service design of the ControHeat jacket.
11. Q: How many stock items of ControHeat jackets does CSI carry?
A: None. CSI stocks only the pattern for each ControHeat jacket.
Delivery time for most ControHeat jackets is normally within 15-17 working days if a
pattern exists and 5 weeks if a new pattern is required. Larger orders with many jackets
can take longer. Emergencies and plant shut-downs are often responded to in less than a
week. These situations should be discussed with personnel when the need arises.
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