Features
• The monostable spool valves in conformity with IEC 61508 Standard (2010 route 2
H
version)
have TÜV (551 series) and EXIDA (551-553 series) certied with integraty levels: SIL 2 for
HFT = 0 / SIL 3 for HFT = 1
• Series 551 versions according to ATEX 2014/34/EU, for zones 0, 1 and 2 and series 553
air-operated versions for zones 1 and 2
• All the exhaust ports of the spool valve are connectable, providing better environmental
protection. Particularly recommended for sensitive areas, such as clean rooms, and
applications in the pharmaceutical and food processing sectors
• The valves offer environmental protection against the ingress of liquids, dusts or other
foreign matter (environmentally-protected construction)
• The solenoid valves satisfy all relevant EU directives
General
Differential pressure 2 - 10,4 bar [1 bar =100
kPa]
Flow (Qv at 6 bar) 1/4 = 860 l/min (ANR)
1/2 = 3000 l/min
fluids ()
temperature range (TS)
seal materials ()
air, inert gas, ltered
551: -40°C to +80°C
VMQ (silicone) + PUR (polyurethane)
553: -40°C to +60°C
Materials in contact with fluid
()
Ensure that the compatibility of the fluids in contact with the materials is verified
Air operated
CNOMO solenoid (pilot)
interface
(551-553 Series) (551 Series)
Body, end covers
Stainless steel, AISI 316L
Stainless steel, AISI 316L
Spool valve internal parts
Stainless steel, POM
Stainless steel, POM
Seals NBR NBR
Pilot internal parts - Size 30 (E06.05.80N),
refer to catalogue pages:
314/LPKF pilot (contact
us) and 195 pilot (LISC)
Air operated specifications
pipe
size
orifice
size
flow
coefficient
Kv
operating pressure
differential (bar)
prefix optional
basic
catalogue
number
min.
max. (PS)
air ()
()
(mm) (m
3
/h) (l/min) -
Pilot air operated - spring return (monostable)
1/4 6 0,75 12,5 2 10 - 551A121
(1)
1/2 13 2,49 41,5 2 10 - 553A121
(1)
Pilot air operated and return (bistable)
1/4 6 0,75 12,5 2 10 - 551A122
1/2 13 2,49 41,5 2 10 - 553A122
CNOMO solenoid (pilot) interface specifications
pipe
size
orifice
size
flow
coefficient
Kv
operating pressure
differential (bar)
power
level
prefix optional solenoids
basic
catalogue
number
min.
max. (PS)
ATEX / IECEx
air ()
Ex db Ex ia
()
(mm) (m
3
/h) (l/min)
~ =
~/=
(2)
LISC
Solenoid air pilot operated - spring return (monostable)
1/4 6 0,75 12,5 2 10 10 BP
l
- 551A221
(1)
1/4 6 0,75 12,5 2 - 8 LP -
m
551B221
(1)
Solenoid air pilot operated and return (bistable)
1/4 6 0,75 12,5 2 10 10 BP
l
- 551A222
1/4 6 0,75 12,5 2 - 8 LP -
m
551B222
Select 8 for NPT ANSI 1.20.3 or select G for ISO G (228/1) ● Available feature m Available feature in DC only.
- Not available
(1)
Certied IEC 61508 Functional Safety data, use sufx "SL".
(2)
314/LPKF: Contact us
80094GB-2019/R01
BP
RP - MP
LP
UP
Not
available 0,5W
Not
available 7,4W - 7,6W
Ultra Low
power
Low
power
Reduced and
Medium power
Basic
power
POWER LEVELS - cold electrical holding values (watt)
ASCO™ Spool Valves
single/dual solenoid - pilot operated or air operated - stainless steel body - 1/4 and 1/2 tapped
5/2
SERIES
551 - 553
Visit our website at www.emerson.com/asco 1