10
Type
(DN = Nominal Pipe Size)
Straight inlet pipe
Straight outlet pipe
Extension
15 x DN
5 x DN
Reduction
15 x DN
5 x DN
90° - elbow
20 x DN
5 x DN
Two 90° - elbows,
in one level
25 x DN
5 x DN
Two 90° - elbows,
in two levels, T-piece
30 x DN
5 x DN
Valve, gate valve
50 x DN
5 x DN
3.4. Required length of straight pipe
The flowmeter should be installed as far as possible from disturbances of the flow. The causes for disturbance
of the flow are for instance, reducers, elbows, T-pieces, valves, gate valves, etc. The specified measurement
accuracy can be achieved only when the following straight inlet and outlet pipe lengths are installed:
•
The stated values are as a minimum. If possible, allow for greater distances.
•
Valves or gate valves should be installed downstream of the flowmeter.
•
With lighter gasses the inlet straight pipe should be longer.
flow direction
straight inlet pipe
nominal pipe size (DN)
straight outlet pipe