Samson 3291, Перевод оригинальной инструкции

Страница: 31 / 96

EB 8072 EN 5-1
Installation
5 Installation
The work described in this section is only to
be performed by personnel appropriately
qualified to carry out such tasks.
5.1 Installation conditions
Work position
The work position for the control valve is the
front view looking onto the operating con
-
trols (including valve accessories).
Plant operators must ensure that, after instal-
lation of the device, the operating personnel
can perform all necessary work safely and
Table 5-1: Inlet and outlet lengths
a x NPS b x NPS
Q
Q Flow rate
a Inlet length
b Outlet length
State of process medium
Valve conditions Inlet length a Outlet length b
Inlet Outlet
Gas
Ma ≤ 0.3 2 4
0.3 ≤ Ma ≤ 0.7 2 10
Vapor
Ma ≤ 0.3
1)
2 4
0.3 ≤ Ma ≤ 0.7 1) 2 10
Saturated steam (percentage of con -
densate > 5 %)
2 20
Liquid
Free of cavitation/w < 10 m/s 2 4
Cavitation producing
noise/w ≤ 3 m/s
2 4
Cavitation producing
noise/3 < w < 5 m/s
2 10
Critical cavitation/w ≤ 3 m/s 2 10
Critical cavitation/3 < w < 5 m/s 2 20
Liquid
Liquid, with
flashing
– 2 20
Multi-phase – 10 20
1)
No saturated steam