5
Installation & Commissioning Instructions
For more information please call us on
01993 824900
or view our website at
www.emmeti.co.uk
Gerpex Press Fit System
Gerpex Press Fit System
2. Installation
2.4 Bend radius
• When forming bends in the pipe please refer to
table 3 to obtain the minimum bend radius.
Pipe
dimension
(Ø x S)
Minimum
radius
of bend r
Min. radius
of bend r
with spring
pipe bender
Min.radius
of bend r
with
hydraulic
bender
14 x 2
5 x Ø
3 x Ø
16 x 2
5 x Ø
3 x Ø
20 x 2
5 x Ø
3 x Ø
26 x 3
8 x Ø
4 x Ø
4 x Ø
32 x 3
4 x Ø
40 x 3.5
4 x Ø
50 x 4
4 x Ø
63 x 4.5
4.5 x Ø
R
Ø
S
x
• For tooling to form bends in Gerpex pipe please
refer to our pricelist.
• It is preferable to use fittings rather than bends for
pipe with greater than 26mm diameter
• When bending pipe please avoid placing any
existing fittings under undue pressure. Please
refer to fig 2.4 which shows the minimum distance
between a fitting and the beginning of a bend.
Minimum distance is 5 x pipe diameter.
2.5 Thermal Expansion
• During installation please pay attention to the
thermal expansion characteristics of Gerpex pipe.
The longitudinal expansion of the pipe is affected
by a variation in temperature and can be calculated
using the following data found in table 4 and Fig. 2.5.
Copper
PE-X polyethylene mesh
PP polypropylene
PB polybutylene
Steel
Inox Steel
.
.
.
.
Gerpex
ΔT
10
20
30
40
50
60
70
L
ΔL
0.1
0.026
0.052
0.078
0.104
0.130
0.156
0.182
0.2
0.052
0.104
0.156
0.208
0.260
0.312
0.364
0.3
0.078
0.156
0.234
0.312
0.390
0.468
0.546
0.4
0.104
0.208
0.312
0.416
0.520
0.624
0.728
0.5
0.130
0.260
0.390
0.520
0.650
0.780
0.910
0.6
0.156
0.312
0.468
0.624
0.780
0.936
1.092
0.7
0.182
0.364
0.546
0.728
1.910
1.092
1.274
0.8
0.208
0.416
0.624
0.832
1.040
1.248
1.456
0.9
0.234
0.468
0.702
0.936
1.170
1.404
1.638
1.0
0.260
0.520
0.780
1.040
1.300
1.560
1.820
2.0
0.520
1.040
1.560
2.080
2.600
3.120
3.640
3.0
0.780
1.560
2.340
3.120
3.900
4.680
5.460
4.0
1.040
2.080
3.120
4.160
5.200
6.240
7.280
5.0
1.300
2.600
3.900
5.200
6.500
7.800
9.100
6.0
1.560
3.120
4.680
6.240
7.800
9.360 10.920
7.0
1.820
3.640
5.460
7.280
9.100 10.920 12.740
8.0
2.080
4.160
6.240
8.830 10.400 12.480 14.560
9.0
2.340
4.680
7.020
9.360 11.700 14.040 16.380
10.0
2.600
5.200
7.800 10.400 13.000 15.600 18.200
In order to calculate the longitudinal expansion please
use the following formula:
ΔL =
α
x L x ΔT
where:
α
is the coefficient of linear expansion, equal to 0.026
mm/m K for insulated pipes;
L is the initial length of the pipe (m);
ΔT is the temperature difference (K).
Example:
Length of pipe: 12 m
Temperature difference: 50 K
ΔL = 0.026 x 12 x 50 = 15.6 mm
Fig 2.4
Table 3
Table 4
Fig 2.5
