Samson 3351 - Page 20

3-6 EB 8039 EN
Design and principle of operation
Table3-5: Control pressure and max. differential pressure Δp
max
The max. differential pressure depends on the control pressure and can be adapted to the
operating conditions by SAMSON before delivery.
Valve size
DN 15 20 25 32 40 50 65 80 100
NPS ½ ¾ 1 – 1½ 2 2½ 3 4
Flowcoefcient
K
VS
6.3 10 14 25 31 40 72 90 170
C
V
7.5 12 16 – 36 47 84 105 200
Max. supply
pressure
DN15to80 8bar/116psi
DN100 6bar/88psi
Standard version (PTFE or PEEK plug seal)
Fail-close
Min. control pressure to
openthevalveatΔp
max
PTFE 4bar/58psi
PEEK 5.5bar/80psi
Max. perm.
differential
pressure
Δp
max
Vapors,gasesAB 20bar/290psi 16bar/235psi 10bar/145psi –
Vapors,gasesBA –
10bar/
145psi
LiquidsBA 16bar/235psi 10bar/145psi 5bar/73psi
Fail-open
Min. control pressure to
closethevalveatΔp
max
PTFE/
PEEK
4.5bar/65psi
Max. perm.
differential
pressure
Δp
max
Vapors, gases,
liquids
20bar/290psi 16bar/235psi 10bar/145psi
Specialversionforfail-closeversionwithreinforcedspringsforhigherdifferentialpressureΔp(PTFEplugseal
only)
1)
Min. control pressure to open the
valveatΔp
max
5.5bar/80psi –
Max. perm.
differential
pressure
Δp
max
Vapors, gases,
liquids
2)
30bar/435psi 20bar/290psi 7bar/102psi –
1)
ThestandardversionwithPEEKisalreadyttedwithreinforcedsprings.Therefore,aspecialversionwithPEEKplug
seal for higher differential pressures is not available.
2)
SeeFig.3-1directionofowBA