379
Dixon Sanitary 2014
800.789.1718
Technical
Sanitary Gaskets
Elastomers available:
Nitrile (Buna N)
Silicone (peroxide cured/platinum cured)
EPDM
FKM
PTFE
Screens and orifice gaskets
(
see page 160 for mesh sizes)
PTFE orifice gaskets are solid PTFE
Certified as required to:
US Pharmacopoeia Class VI
Cytotoxicity Criteria
Title 21CFR177.2600 & .1550
USDA and 3A Sanitary Standards
All elastomeric gaskets require periodic replacement. Gasket life is influenced by the gasket material, product
application, temperature, cleaning procedures, etc. After monitoring gasket conditions in a process system, a
schedule should be developed for replacement of gaskets.
Elastomer
Part Number Identifier
Typical
Color
Color Code
Useful Temperature
Buna-N
U
black
1
red dot
-25
°F to 225°F
Buna-N
UW
white
1
red dot
-25
°F to 225°F
EPDM
sulfur cured
E
black
1
green dot
-40
°F to 275°F
EPDM
peroxide cured
E
black
3
green dots
-40
°F to 275°F
FKM
SFY
black
brown
1
white dot
1
yellow dot
-15
°F to 375°F
Silicone
peroxide cured
XW
white
1
pink dot
-50
°F to 400°F
Silicone
platinum cured
XC
clear
none
-50
°F to 400°F
PTFE
G
white
none
-10
°F to 300°F
PTFE
w/50% 316 particles
GTS
silver
none
-20
°F to 450°F
Color Coding - Identification of Gasket Materials
Packaging and Storing Information
The shelf life of rubber gaskets is the maximum period from cure date to the date the product is installed. During the shelf life
time, the rubber product is expected to retain its characteristics under the following conditions:
•
stored in original packaging in a clean, dry warehouse
•
not exposed to direct sunlight
•
stored no closer than 6' from electric motors
•
temperature between
65
°F
to
85
°F
A guideline for shelf life of rubber gaskets manufactured from the following components should have the following shelf life not to
exceed:
•
Buna
10
years
•
EPDM
10
years
•
FKM
10
years
•
Silicone
5
years
•
PTFE
20
years
Y