
FEATURES
n
H-900 is available as CE/PED products
n
316 St.St. Construction
n
Service 10-225 psi
n
MAWP* 300 psi
n
One spring for all set pressure range
n
Available in all pipe threads and LET-LOK® connectors
n
Sizes: 1/4" or 6mm
* Maximum Allowed Working Pressure.
GENERAL
The H-900 series is a relief valve for low pressure service.
The valve is normally closed. It will open when the system pressure
reaches the set level. It will re-close when the system pressure falls
below the set level.
1
2
3
VALVES & ACTUATORS
MATERIALS OF CONSTRUCTION
Item No. Components Qty. Valve Body Material
Cap Plug 1 Polypropylene
1
Adjustment Cap
2
Cap Lable 1 Polyester
3
Locking Nut
4
Upper Spring Button
5
Spring
6
Lower Spring Button 1 St.St. 316
7
Bonnet 1 St.St. 316
8
O-ring
9
O-ring 1 Fluorocarbon FKM
10
Retaining Ring
11
Stem 1 St.St. 316
12
Bonded Poppet
13
Insert 1 St.St. 316
14
Packing
15
Ring 1 St.St. 316
16
Body
17
STANDARD CONFIGURATION DIMENSIONS
Connection / size
Description
H-900
H-900
H-985
H-995
Inlet Outlet
1/4 LET-LOK®1/4 LET-LOK
6MM LET-LOK®6MM LET-LOK
1/4 Male NPT 1/4 Female NPT 32 1.26 30 1.18 40 1.57 88.6 3.49
1/4 Male NPT 1/4 LET-LOK
1 St.St. 316
1 St.St. 316
1 St.St. 316
1 St.St. 302
1 Fluorocarbon FKM
1 PH15 - 7 Mo
1 St.St. 316 Bonded with Fluorocarbon FKM
1 PTFE
1 St.St. 316
Orifce
mm inch mm inch mm inch mm inch mm inch
®
®
4.8 0.19
®
ABCD
37 1.45 39 1.53 50 1.97 96 3.78
37 1.45 39 1.53 50 1.97 96 3.78
32 1.26 39 1.53 50 1.97 88.6 3.49
Dimensions
4
5
6
7
8
9
10
11
12
13
Lock
Wire Holes
B
C
RELIEF VALVES H-900 SERIES
284
D
A
14
15
16
17

CLEANING & PACKAGING
Every H-900 series Relief valve is cleaned in accordance
with Standard Cleaning and Packaging (procedure 8184).
Oxygen Clean & Lubricant Free Cleaning and packaging, in
accordance with Special Cleaning and Packaging
(procedure 8185), is available as an option.
TESTING
The HAM-LET H-900 Relief Valve designs have been tested for
Proof and Burst.
Every H-900 Relief Valve is factory tested for proper set and
resealing preformance.
PRESSURE TEMPERATURE RATING
Series H-900 Size: 1/4"
Seal Meterial Fluorocarbon FKM Buna N Polychloroprene (CR) EPDM
TEMP °C (°F)
-40 (-40) - - -
-34 (-30) - -
-23 (-10) -
-18 (0)
-12 (10)
-4 (25)
-1 (30)
10 (50)
65 (150)
93 (200)
121 (250)
135 (275)
148 (300) -
225 (15.5)
SETTING AND RESEALING PRESSURE
n
Upstream set pressure is the rst indicator of ow process.
Every pressure relief after the rst indication is repeatable within
a deviation of 5% at room temperature.
n
Blocked upstream set pressure is the rst indicator of a stopped
ow process and is always lower than the set pressure.
n
Calculation of set pressure valve design demands
back pressure consideration as the system back pressure
increases the set pressure. To balance the system, the back pressure
must be multiplied by 0.8 and the result shall be subtracted from
the required set pressure.
n
Lubricant free cleaned valves have higher reseal pressure
MAX SET PRESSURE psig (bar)
225 (15.5)
225 (15.5)
225 (15.5)
H900 RESEAL PRESSURE
FLOW DATA AT 70°F (20ºC)
Series
Orice in fully open mode is 4.8mm (0.19 inch)
SPRING 10-225psig
WATER FLOW AIR FLOW
Water Flow (LPM)
Pressure Drop (Psi)
Water Flow (US.GPM)
Pressure Drop (bar)
H-900
300
250
200
150
100
Inlet Pressure (Psi)
50
Test Set Pressure
10 - 20 (0.68 to 1.3) 50
175 - 225 (12.0 to 15.5)
0
100 200
225 psi
0
0
24
psig (bar)
Air Flow (SLPM)
Air Flow (SLPM)
150 psi
100 psi
6 8 10
Air Flow (SCFM)
Min Resealing Pressure
Percentage of set
300 400 500
50 psi
12 14
as a
pressure, %
90
VALVES & ACTUATORS
20.7
17.2
13.8
10.3
6.9
Inlet Pressure (bar)
3.5
0
16 18 20
HAM-LET ADVANCED CONTROL TECHNOLOGY
285

APPLICATIONS
H-900 relief valves gradually open when pressure
increases.
As such, they are not certied to ASME due to not having
capacity rating at a given pressure rise (accumulation).
H-900 SERIES ORDERING INFORMATION
OPERATION
H-900 relief valves open when the system pressure gets to the set
pressure and close when the system pressure drops below the set
pressure.
Warning
Valves that were not actuated for some time may contain
n
pressure higher than the set pressure.
System designer and users shall determine what system
n
applications require using relief valves to meet specic safety
codes and which valves conform to such codes.
OPTIONAL
VALVES & ACTUATORS
Valve Series
Valve Type
- LET-LOK® Ends
00
- Male to Female End
85
- Male to LET-LOK
95
H - 9
00
®
End
-
Body Material
- 316St.St.
SS
End Connection
- LET-LOK®
L
- NPT
N
- ISO Tapered
R
- NPT to LET-LOK
NL
For other end connections,
please contact HAM-LET
representative.
®
- --
LSS SL1/4
End Connection Size
1/4 6MM
Spring Designator
- Silver Code For Spring
SL
Range 10 - 225 psi
Factory Calibration
Designator
10-225 Psi
Example: H-900-SS-L-1/4-SL120
Will be Calibrated to 120 Psi
ORDERING INFORMATION FOR SPARE KITS
SPRING KIT SEAL KIT
Includes: Spring, Label, Wire and Lock
Includes: O-rings, Bonded Poppet and Label
--
Seal Material
- Fluorocarbon FKM
BLANK
- Buna N
BU
- EPDM
EP
-
NE
CE/PED Certification
BLANK
CE
Treatment
BLANK - Standard Cleaning &
OC - Oxygen Clean
LF - Lubricant Free
Polychloroprene (CR)
- Standard testing
- Certication PED
97/23/EC
Passivation
-
Z - 900 - SPK - 1/4
Body Designator
per End Connection
1/4 for all end connections
n For oxygen applications work shall be carried out according to procedures for
working with oxygen. In case spare kits are ordered for oxygen clean valves, such
kits have to be ordered as oxygen clean by adding "-OC" designator.
Example: Z-900-SK-1/4-VI-OC
Warning!
The system designer and user have the sole responsibility for selecting products suitable for their special
application requirements, ensuring their safe and trouble-free installation, operation, and maintenance. Application details, material compatibility and product ratings should all be considered for each selected product.
Improper selection, installation or use of products can cause property damage or personal injury.
RELIEF VALVES H-900 SERIES
286
Z - 900 - SK - 1/4 - VI
Body Designator
per End Connection
1/4 for all end connections
Seal Material
- Fluorocarbon FKM
VI
- Buna N
BU
- EPDM
EP
- Polychloroprene (CR)
NE
H-900
, Rev.11,
January 2015