Water supply
RU EN

Energy industry


Modern energy-efficient solutions require modern materials. RU-FLEX synthetic rubber-based foam insulation meets the high requirements of the energy industry. The insulation is durable and reliable, exceeding the service life of alternative materials, and has proven itself in the best possible way.

Efficient insulation of water supply systems makes it possible to maintain the required supply water temperature no matter how long the pipe. Correct calculation through use of the modern RTK-PROJECT calculation software, as well as the stable thermal and technical characteristics of RU-FLEX foam rubber insulation, guarantee long-term operation of water supply systems in an optimum mode.

To help choose the right RU-FLEX ST insulation thickness, we have prepared ready-made solutions (basic calculations).

Problem and solution

Calculation of insulation thickness according to normative heat flux density.

Initial data

  • Heat transfer medium: water
  • tm = 60 ˚С – coolant temperature in the pipe;
  • tо = 25 ˚С –temperature in the shopping center.

According to SP (Construction Regulations) 61.13330.2012 "Thermal insulation of equipment and pipelines" paragraph 6.12: it is allowed to accept the nearest lower thickness of the thermal insulation layer in cases of calculation of temperature on the insulation surface and heat flux density norms, if the difference between the calculated and nominal thickness does not exceed 3 mm.

Without covering layer or with covering layer in different colours (PROM FORM):
Steel pipe diameter, mm Operating mode (24-hour or heating period) Design thickness of insulation, RU-FLEX ST, mm Recommended insulation thickness, RU-FLEX ST, mm
57 > 5000 hours
(209 days or more)
24.85 T25
≤ 5000 hours
(208 days or less)
21,43 T19
76 > 5000 hours
(209 days or more)
26,96 Т25
≤ 5000 hours
(208 days or less)
23,47 Т25
With foil-coated cover layer (ALU, PROM FORM silver, PROM ALU):
Steel pipe diameter, mm Operating mode (24-hour or heating period) Calculated insulation thickness, RU-FLEX ST PROM ALU, mm Recommended insulation thickness, RU-FLEX ST PROM ALU, mm
57 > 5000 hours
(209 days or more)
22,95 Т25
≤ 5000 hours
(208 days or less)
19,52 Т19
76 > 5000 hours
(209 days or more)
25,09 Т25
≤ 5000 hours
(208 days or less)
21,59 Т19

T-Designation of the tubular material.
Calculations made according to SP 61.13.330.2012 RF

Calculation of insulation thickness according to a given temperature on the insulation surface.

Initial data

  • Heat transfer medium: water
  • tm = 60 ˚С – coolant temperature in the pipe;
  • tо = 25 ˚С –temperature in the shopping center.

According to SP (Construction Regulations) 61.13330.2012, paragraph 6.7.1: for insulated surfaces located in working or service areas of rooms and containing substances with a temperature of 150 °C or lower, the surface temperature of the thermal insulation should not exceed 40 °C.

Without covering layer or with covering layer in different colours (PROM FORM):
Steel pipe diameter, mm Insulation surface temperature not exceeding ˚C Design thickness of insulation, RU-FLEX ST, mm Recommended insulation thickness, RU-FLEX ST, mm
57 40 4,18 Т9
76 4,24 Т9
With foil-coated cover layer (ALU, PROM FORM silver, PROM ALU):
Steel pipe diameter, mm Insulation surface temperature not exceeding ˚C Calculated insulation thickness, RU-FLEX ST PROM ALU, mm Recommended insulation thickness, RU-FLEX ST PROM ALU, mm
57 40 6,89 Т9
76 7,05 Т9

T-Designation of the tubular material

In buildings intended for permanent occupancy, the temperature of the thermal fluid does not exceed 110°C. According to SP (Construction Regulations) 61.13330.2012, thermal insulation materials of flammability groups G3 and G4 may not be used for equipment and pipework.

RU-FLEX ST technical insulation has a flammability group G1 and an operating temperature range from -200 to + 110 °C, which fully complies with the requirements of regulations and codes of practice for technical insulation in residential buildings

Calculations made according to SP 61.13.330.2012 RF

Calculation of insulation thickness to prevent condensation from ambient air on the thermal insulation cover layer.

Initial data

  • Heat transfer medium: water
  • tm = +5 ˚С – coolant temperature in the pipe;
  • tо = +20 ˚С – temperature in the shopping center.
  • φ = 65 % — the relative humidity in the shopping centre.
Without covering layer or with covering layer in different colours (PROM FORM):
Steel pipe diameter, mm Design thickness of insulation, RU-FLEX ST, mm Recommended insulation thickness, RU-FLEX ST, mm
33,5 5,11 Т6
89 5,49
159 5,62 Р9/(Т9, Р6, Р6 )
219 5,67
With foil-coated cover layer (ALU, PROM FORM silver, PROM ALU):
Steel pipe diameter, mm Calculated insulation thickness, RU-FLEX ST PROM ALU, mm Recommended insulation thickness, RU-FLEX ST PROM ALU, mm
33,5 7,01 Т9
89 7,68
159 7,93 Р9 / Т9

Calculations made according to SP 61.13.330.2012 RF