Roxul Industrial Insulation Process - Manual (Page 63)

The applicable standards and regulations must
also be observed. A few examples follow:
ASTM C1696 "Standard Guide for Industrial
Insulation Systems"
NACE SP0198 (Control of corrosion under
thermal insulation and fireproofing materials -
a system approach)
MICA "National Commercial & Industrial
Insulation Standards"
DIN 4140 (Insulation works on industrial plants
and building services installations)
AGI Q05 (Construction of industrial plants)
AGI Q101 (Insulation works on power plant
components)
CINI-Manual: “Insulation in industry”
BS 5970 (Code of practice for the thermal
insulation of pipework, ductwork, associated
equipment and other industrial installations)
PIP (Process Industry Practices)
Insulation selection
Storage tanks are located outdoors, so it is
important to select a material with a low thermal
conductivity and excellent water repellent
properties. ProRox
® semi rigid boards (slabs) can be
used to insulate tank walls. Applying a less water
repellent, non pressure-resistant insulation like
wired mats are not generally recommended. If foot
traffic can occur, a pressure-resistant board (slab)
such as ProRox
® SL 590 NA is applied for the
insulation of the tank top. If applying a product which
is resistant to foot traffic is impossible, apply a
support structure, where needed, to protect the
insulation boards (slabs). For temperatures above
210 °F (100 °C) applying the insulation in at least 2
layers (e.g. masonry bond pattern) is recommended.
Insulation of tank tops
Insulating a tank is not easy. Corrosion of the tank
top can occur if the insulation is not properly
installed and maintained. Therefore, some
companies tend not to insulate the tank top.
A common assumption is that the still air above
the hot fluid acts as insulation of the tank top. This
assumption is, however, not entirely correct. Due
to the difference in temperature between the hot
fluid and the non-insulated tank top there is fairly
strong convection, resulting in considerable heat
loss. Tank top insulation is feasible if the proper
insulation material and mounting and fixing
methods are applied.
Construction
Before starting the insulation works, ensure that
all preparatory work on the object has been
completed. Refer to Chapter 1.1 for details.
Outdoor storage tanks are continuously exposed
to the environment. Wind causes both pressure
and delamination, which can easily result in
damage to the insulation protection – usually
aluminum sheeting. Consequently, the aluminum
sheeting is blown away and rain water can leak
into the insulation. Water accumulation can cause
corrosion resulting in severe corrosion of the tank,
leakage of the substance inside etc. Correct
precautions are necessary to ensure the quality
and life-time of the insulation.
Many systems can cope with the demands. The
appropriate system will greatly depend on the
diameter, temperature tank, the surrounding
environment and the possibilities to use
scaffolding/rope access when mounting the
insulation. In addition, the plant owner may have
specific requirements. Determine whether the
products and construction described are suitable
for the corresponding application in each
individual case. If in doubt, consult the ROXUL
®
Technical Services Team.
1.5 Insulation of storage tanks
1. No insulation: strong convection - 2. Insulation:
reduced convection - 3. ProRox
® insulation
60