1. HYDRAULIC HOSES

2. Nowadays almost all road-building, municipal and other Russian and foreign vehicles have hydraulic transmission.
Hydraulic transmission break down rarely, but from time to time it is necessary to change the old details, including hydraulic hoses.
We would like to tell about the possibility to replace the foreign hoses to Russian ones. Nowadays Russian specialists use foreign hydraulic transmission, but the European standards are not so much known. It is more convenient to use Russian hoses.

3. There are 2 types of hydraulic hoses used in industry: skive hoses and spiral hoses.
Skive hoses are used in hydraulic transmissions with high pressure – till 25 megapascals and with small radius of flexure.
Spiral hoses are used in hydraulic transmissions with the pressure of megapascals and with constant cycle charge.
The European standards for skive hoses are DIN EN 853 and DIN EN 857, and they are almost similar to Russian GOST These standards are for the hoses which work with hydraulic mineral oils, engine propellant with temperatures from -40 to +100 C, and also for water and oil emulsion with temperatures from -40 to +70 C.
These requirements are convenient to Russian hydraulic hoses.

4. There are 4 types of hoses DIN EN 853:
1SN and 2ST – skive hoses
1SN and 2SN – the same construction, but thinner external rubber layer. This permits to armour the hoses without preparatory cleaning of external rubber layer.
The essential difference between foreign and Russian hoses is DN, which is fixed in inches. It is not always the same as Russian. For instance, the diameter of foreign hose with DN12 is 12,7 mm, which is larger than Russian one. At the same time DN10 and DN12 are 9,5 mm and 19 mm and they can allow 11% less liquid than Russian ones.

5. Leak resistance pressure
The testing of Russian hoses on leak resistance and rupture (megapascals): DN
Max pressure
Leak resistance pressure
Rupture pressure
1ST and 1SN
2ST and 2SN
2 ST and 2SN 5
250
415
500
830
1000
1650 8
225
400
450
800
900
1600
215
350
430
700
850
1400 10
180
330
360
660
720
1320 12
160
275
320
550
640
1100 16
130
260
520 19
105
210
420 25 88
165
175
325
650 31 63
125
150 38 50 90
100
200 51 40 80 32

6. The marking of the hoses DIN EN 853 is the following:
Producer
Type
Caliber (in inches)
Standard
Nominal diameter
The last 2 figures of the producing year
The pressure is not marked, it is determined in the schedule. There are 2 types of DIN EN 857 hoses: 1SC and 2SC. Their characteristics are the same as DIN EN 853, but the bend radius is 40% less.
There are 4 types of spiral hoses DIN EN 856:
Type 4SP – 4-spiral skive hoses for middle-level pressure
- Type 4SH – 4-spiral skive hoses for high pressure

7. Leak resistance pressure, bar
Type R12 – 4-spiral hose for long work with high temperature and middle-level pressure
Type R13 – 6-spiral hose for the most hard and long work with very high pressure. Its production is limited. ND
Max pressure
Leak resistance pressure, bar
Rupture pressure, bar
4SP
4SH
R12
R13 16
350 -
276
700
552
1400
1104 19
420
345
840
690
1680
1380 25
280
380
560
760
1120
1520 31
210
325
207
650
414
1300
828 38
185
290
172
370
580
344
740
1160
688 51
165
250
330
500
660
1000

8. DIN EN 856 have min temperature -40C
ND, mm
Min bend radius, mm
4SP
4SH
R12
R13 6
150 - 10
180
130 12
230 16
250
200 19
300
280
240 25
340 31
460
420 38
560
500 51
660
700
630
830
DIN EN 856 have min temperature -40C

9. The characteristics of type 4SP:
Nominal inside diameter
Rupture pressure, bar
Pressure according GOST
The number of cycles with Rmin
GOST
EN 856 10
1400
1780
340 12
1360
1660 16
300
800000 19
1200
250 25
1000
1120
The hydraulic hoses satisfy the requirements of the customers and can be used both in Russian and foreign machines. The quality and technical control is made during all periods of production. Then the hoses are tested on the testing stand.