PRESSURE
-------------------------------- 1m head of water = 9810N/m²
= 0.00981N/mm²
= 9.81KN/m²
1 bar= 10>⁵N/m²
= 14.5 lbf/in²
LENGTH
-----------------------------
1m = 3.281ft1
yd = 0.9144 m
1 ft = 0.3048 m
1in = 25.4 mm
MASS
--------------------------------------
1kg = 2.205 lbs
1lb= 0.45369 kg
1 tonne = 0.984
U.K ton.= 1000kg
AREA
--------------------------------------
1 hectare = 10.000m²
=2.471 acres
1yd² = 0.8361m²
1 ft² = 0.0929 m²
WORKING PRESSURE AND
EFFECTS OF TEMPERATURE
Maximum working pressure is based on class
of pipe at 25°c calculated from known data on the basis
of 50 years of continuous operation.
Reduce by 2% every 1°c rise in temperature
for PVC pressure pipe and fittings.
Use applicable factor for PE pressure
pipes and fittings up to 60°c
Do not use PVC and PE pressure pipe and
fittings for temperature in excess of 60°c
CI 4
CI 6
CI 10
CI 12
CI 16
POLYETHYLENE DERATING
FACTORS
Water Temperature °c
Factor applied above 25°c
0 - 25
1
25 - 30
0.8
30 - 35
0.63
35 - 40
0.4
40 - 45
0.32
45 - 60
0.25
Material
Abbreviation
Remarks
Maximum Permissible
Temperature
(Water)
Constant
Short term
Unplasticed Polyvinyl Chloride
u-PVC
Resistant
to most solutions of acids, alkalis, and salts and to
organic compounds miscible with water. Not resistant to
aromatic and chlorinated hydrocarbons.
60°c
60°c
High Density Polyethlene
HDPE
Resistant
to hydrous solutions of acids, alkalis and salts as well
as to a large number of organic solvents .Unsuitable for
concentrated oxidising acids.
