Pre-insulated pipes

Pre-insulated pipe is a single structure consisting of the main steel pipe (black steel pipe or galvanized steel pipe), heat-insulating polyurethane foam layer and galvanized or polyethylene mantle pipe.

“SarmatTermoEngineering” construction company (subsidiary of “Sarmat” holding company) manufactures:


Black pipe with polyethylene sheath – ÏÝÍÄ


Galvanized pipe with polyethylene sheath - Ö ÏÝÍÄ


Black pipe with galvanized sheath - ÎÑ


Galvanized pipe with galvanized sheath - Ö ÎÑ







Ïðåäâàðèòåëüíî èçîëèðîâàííûå òðóáû


“SarmatTermoEngineering” construction company (subsidiary of “Sarmat” holding company) manufactures pre-insulated pipes and shaped objects with metal mantel (galvanized steel) for above-ground pipelining and pipes with polyethylene mantel for underground pipelining.


Benefits of PI-pipes (in comparison with usual pipes):


Reduction of heat loss (from 45% to 2%)
Reduction of annual operational costs for pipeline maintenance (in 9-10 times)
Increased service life (up to 30 years)
Reduction of costs for current pipeline maintenance (in 3 times)

The quality of PI-pipe manufactured by “SarmatTermoEngineering” construction company (subsidiary of “Sarmat” holding company) is provided by high-quality completion materials and manufacturing process. The manufacture of PUF insulation requires adherence to many parameters: temperature conditions, components gauging and ratio, preparatory treatment of pipe and polyethylene sheath.


The following pipes are used in the pre-insulated pipeline systems:

With polyethylene sheath:


Black pipe with polyethylene sheath - ÏÝÍÄ

It is used for heating systems, laid under ground


Nominal size and weight of PI-pipes for underground pipelining
(main pipe – black, steel; mantel pipe - polyethylene)

Nominal size
of PI-pipes
Steel pipe parameters Parameters of polyethylene mantel pipe Weight of 1 ì.ï.
PI-pipe, kg
Outer diameter
d, mm
Minimal wall
thickness Smin, mm
Outer diameter d, mm Wall thickness S, mm
38/110 38 3,0 110 2,5 3,8
45/110 45 3,0 110 2,5 4,2
57/125 57 3,5 125 2,5 6,5
76/140 76 3,5 140 3,0 8,5
89/160 89 4,0 160 3,0 10,1
108/200 108 4,0 200 3,2 14,3
114/200 114 4,0 200 3,2 14,8
133/225 133 4,0 225 3,5 17,6
159/250 159 4,5 250 3,9 22,5
219/315 219 6,0 315 4,9 39,9
273/400 273 7,0 400 6,3 59,7
325/450 325 8,0 450 7,0 79,0
377/500 377 9,0 500 7,8 101,1
426/560 426 7,0 560 8,8 96,5

Galvanized pipe with polyethylene sheath - Ö ÏÝÍÄ

It is used for hot water supply systems, laid under ground.


Nominal size and weight of PI-pipes for underground pipelining
(main pipe – galvanized, steel; mantel pipe - polyethylene)

Nominal size of PI-pipes Galvanized steel pipe parameters Mantel pipe parameters Weight of 1 ì.ï. PI-pipe, kg
Nominal inside diameter d, mm Outer diameter d, mm Minimal wall thickness Smin, mm Polyethylene
Outer diameter d, mm Wall thickness S, mm
25/90 25 33,5 3,2 90 2,2 3,4
32/110 32 42,3 3,2 110 2,5 4,8
40/110 40 48,0 3,5 110 2,5 5,4
50/125 50 60 3,5 125 2,5 6,8
65/140 65 76 4,0 140 3,0 9,3
80/160 80 89 4,0 160 3,0 11,2
100/200 100 114 4,0 200 3,2 14,8
125/255 125 140 4,5 200 3,5 17,6
150/250 150 165 4,5 225 3,9 22,5

With galvanized sheath:


Black pipe with galvanized sheath - ÎÑ

It is used for hot water supply systems, laid under ground.


Nominal size and weight of PI-pipes for above-ground pipelining
(main pipe – black, steel; mantel pipe – galvanized, steel)

Nominal size
of PI-pipes
Steel pipe parameters Parameters of polyethylene mantel pipe Weight of 1 ì.ï. PI-pipe, kg
Outer diameter d, mm Minimal wall thickness Smin, mm Outer diameter d, mm Wall thickness S, mm
38/110 38 3,0 110 2,5 4,8
45/110 45 3,0 110 2,5 5,2
57/125 57 3,5 125 2,5 7,8
76/140 76 3,5 140 3,0 9,8
89/160 89 4,0 160 3,0 11,5
108/200 108 4,0 200 3,2 15,8
114/200 114 4,0 200 3,2 16,3
133/225 133 4,0 225 3,5 19,1
159/250 159 4,5 250 3,9 24,3
219/315 219 6,0 315 4,9 40,8
273/400 273 7,0 400 6,3 59,5
325/450 325 8,0 450 7,0 77,1
377/500 377 9,0 500 7,8 97,2
426/560 426 7,0 560 8,8 91,2

Galvanized pipe with galvanized sheath - Ö ÎÑ

It is used for hot water supply systems, laid above ground


Nominal size and weight of PI-pipes for underground pipelining
(main pipe – galvanized, steel; mantel pipe – galvanized, steel)

Nominal size of PI-pipes Galvanized steel pipe parameters Mantel pipe parameters Weight of 1 ì.ï. PI-pipe, kg
Nominal inside diameter d, mm Outer diameter d, mm Minimal wall thickness Smin, mm Polyethylene
Outer diameter d, mm Wall thickness S, mm
25/90 25 33,5 3,2 90 2,2 4,6
32/110 32 42,3 3,2 110 2,5 5,8
40/110 40 48,0 3,5 110 2,5 6,7
50/125 50 60 3,5 125 2,5 8,2
65/140 65 76 4,0 140 3,0 10,6
80/160 80 89 4,0 160 3,0 12,8
100/200 100 114 4,0 200 3,2 16,6
125/255 125 140 4,5 200 3,5 19,1
150/250 150 165 4,5 225 3,9 24,3


Application of PI-pipes manufactured by “SarmatTermoEngineering”:


Underground and above-ground pipelining of heat and utility networks
Heat and cold insulation of industrial pipelines, steam condensers, pipelines for chemical water cleaning, mazout lines and so on with temperature range +25 - +130°C˚Ñ (at special order – up to +400°C˚Ñ).

Application of PI-pipes manufactured by “SarmatTermoEngineering” is regulated by:


STB (National Standard of the Republic of Belarus) 1295-2001 Steel pipes pre-insulated with polyurethane foam;
Construction Norms and Regulations 2.04.07-86 Heat networks;
Construction Norms and Regulations 2.04.14-88 Heat insulation of equipment and pipelines;
Construction Norms and Regulations 3.05.03-85 Heat networks.


Every set of PI-pipe shaped parts manufactured by “SarmatTermoEngineering” passes acceptance testing in special accredited laboratory for compliance with STB (National Standard of the Republic of Belarus) 1295-2001 standards and technical requirements of manufacturer.


All practical questions of designing PI - pipeline systems are covered in “Sarmat” Ltd. publications:

Ðåêîìåíäàöèè ïî ïðîåêòèðîâàíèþ ÏÈ-òðóá

“Recommendations for PI -pipeline designing”
Êàòàëîã ïðåäâàðèòåëüíî èçîëèðîâàííûõ òðóá «ÑàðìàòÒåðìîÈíæèíèðèíã»

“Catalogue of pre-insulated pipes manufactured by “SarmatTermoEngineering”
Èíñòðóêöèÿ ïî ìîíòàæó ñèñòåì åäâàðèòåëüíî èçîëèðîâàííûõ ïåíîïîëèóðåòàíîì òðóáîïðîâîäîâ äëÿ òèïîðàçìåðîâ 25/90-630/800

“Manual for system assemblage of pre-insulated with foam polyurethane pipelines of nominal size 25/90-630/800”
Èíñòðóêöèÿ ïî ïðîåêòèðîâàíèþ, ìîíòàæó è ýêñïëóàòàöèè ñèñòåìû ÎÄÊ

“Manual for designing, assemblage and operating of ROM system”


You can ask a question to get additional information about application of “SarmatTermoEngineering” pre-insulated pipeline systems.