personnel protection is typically installed.
For personnel protection insulation, BP analyzed operating data trends to determine if equipment operated at or above the maximum allowed
surface operating temperature. The following
four questions were answered to determine the
need for personnel protection insulation.
1. Did the temperature of the fluid passing
through the equipment get high enough
in the past 365 days for a duration long
enough to heat the equipment above the
acceptable surface operating temperature?
2. Are there planned changes to the process
(i.e. new wells or new units) in which
temperature of the fluid is expected to see
a change taking it beyond the acceptable
surface operating temperature?
3. Is the equipment normally accessible
to human touch? (e.g. a height of 0 to 7
ft above walking levels and laterally 0 to
18 in. from any walkway or walk space)
4. Is the fluid inside the equipment stagnant
or at a dead end?
options, minimize CUI risk
Insulation is used in industry on many types
of equipment including pressure vessels, tanks,
piping, buildings, structural steel, and junction
boxes. Insulation typically has one or more
purposes based on assumptions made during
design and in general is used to keep the equipment from contacting the atmosphere directly.
Heat/cold conservation is a common type
of insulation used to decrease the heat lost to
or gained from the environment. This type of
insulation is used to help maintain process
temperature and acts as personnel protection. If
insulation is required for process temperature
reasons, then choose an insulation material and
design that will minimize the chance of CUI.
The following are insulation considerations
for minimizing the impact of CUI:
1. Only install insulation where it is necessary
2. Ensure you have a robust insulation
specification and quality control plan
for insulation installation
3. Choose an insulation material with low
moisture permeability and low water
4. Minimize the use of insulation blankets;
where insulation blankets are used, ensure they are installed with the seam at
the bottom and/or a drain hole at the
bottom to allow water to drain
5. Design insulation installation to allow
water to drain
6. Minimize or eliminate insulation on flang-es/bolting, valves, and instrumentation
7. Minimize insulation penetrations (e.g. sup-
ports, nozzles); ensure adequate spacing
between insulated equipment and adjacent
structures/equipment to allow for the in-
stallation of insulation without incurring
penetrations to the insulation jacketing;
consider using load bearing insulation on
piping to eliminate insulation penetrations
8. Ensure coating under the insulation is appropriate and is applied correctly
9. Create and execute an insulation maintenance strategy
10. Consider installing shelters around high
consequence insulated equipment to
prevent precipitation from contacting
11. Design insulation supports to allow
drainage and minimize contact with
12. Choose a jacket material that does not
interfere with CUI NDE.
Personnel protection is installed on equip-
ment where the temperature could cause injury
if personnel came in contact with it and insula-
tion for heat/cold conservation is not required.
Where personnel protection is required, the
following are solutions to consider.
For protective cage with standoffs, choose a de-
sign that allows visual inspection to be performed
(i.e. use expanded metal cage and not perforated
jacket), and minimizes crevice corrosion risk
between the standoff and the pipe/vessel.
For insulative coating, consider tempera-
ture limit of coating, and consider temperature
cycles during startup/shutdown of equipment
when choosing a coating. Coating failure can
occur if the rate of change in temperature exceeds what the coating can handle.
If insulation must be used for personnel protec-
tion, pick a material and design that will minimize
the chance of CUI. Where personnel protection
is required on very hot equipment, protective
cage may not work. If the equipment operating
temperature is too high, the protective cage may
reach temperatures higher than the maximum
allowed surface operating temperature.
Where insulation is installed as a barrier be-
tween a potential release of flammable fluid and
a very hot surface, the protective cage cannot
Where there is a differential temperature
between the equipment and the ambient air,
condensation can occur and cause external
corrosion issues. Insulation (or insulative coating) to prevent condensation can be installed on
Acoustic insulation can be used to mitigate
noise from process equipment. Typically, this
type of insulation is localized (e.g. on a valve).
An alternative to insulation is mandating hear-
ing protection or double hearing protection
around the equipment.
Insulation materials and their properties
var y greatly. Generalized properties of typical
• Mineral wool: retains water, cost ef fective,
very good insulating properties
• Closed cell foam glass: should not retain
water, high material/installation cost,
moderate insulating properties
• Calcium silicate: retains water, moderate
material/installation cost, good insulating
• Cellular perlite: should not retain water,
high material/installation cost, moderate
• Flexible elastomeric foam: should not
retain water, high material/installation
cost, moderate insulating properties
• Insulation blankets: retains water, high
material/installation cost, low insulating
• Insulative coatings: should not retain
water, high material/installation cost,
various insulating properties.
Findings and conclusion
BP has evaluated piping insulation for sev-
eral assets and the table shows results for
four offshore platforms. It was found that
approximately half (~51%) of the number of
evaluated lines can have the insulation re-
moved or replaced with cage or coating.
CUI imposes high safety and financial risks
to a facility. It can be seen from the methodology implemented above that the risks and
costs associated with CUI can be significantly
reduced by utilizing operating conditions and
field data. In summary, removal of the insulation where not required will reduce the likelihood of process safety consequences and/
or financial losses due to plant shutdowns
(production losses) and repair costs. •
Muhannad Rabeh, B.Sc., is a Principal Process Engineer in the Discipline Engineering Team supporting
the Gulf of Mexico operations for BP America.
Shawn O’Hearn, P. Eng., API 510/570, is Inspection
Engineer supporting deepwater operations in the Gulf
of Mexico for BP America.
Jonathan Petersen, CEng, IMechE, Senior Integrity
Management Engineer, supports deepwater operations in the Gulf of Mexico for BP America. He has
25+ years of experience in engineering and integrity
management positions in the oil and gas refining and
Lines with insulation to be permanently removed
(with respect to the total of lines evaluated)
31% 24% 47% 10%
Lines with insulation to be replaced with burn cage or
coating (with respect to the total of lines evaluated)
42% 44% 14% 26%