Parker Phastite PH-4-PS, Installation Manual, Page: 8 / 35

11
General selection criteria
Phastite
®
tube connectors have been designed to work in a wide variety of applications that demand the utmost in
product performance. Although Phastite
®
connectors have been engineered and manufactured to consistently provide
this level of reliability, no system integrity is complete without considering the critical link, tubing.
The Phastite
®
connector is designed to work with commercial tubing with standard wall thicknesses and is offered in 4
different materials:
• 316 Stainless Steel
• INCONEL
®
Alloy 625
• INCOLOY
®
Alloy 825
• Super Duplex
This guide is intended to assist the designer to properly select and order the correct tubing. Proper tube selection and
installation are key ingredients in building leak-free reliable tubing systems. The most important consideration in the
selection of suitable tubing for any application is the compatibility of the tubing material with the media to be contained.
In addition, tubing compatibility with the connector is mandatory, as dissimilar materials in contact may be susceptible
to galvanic corrosion. The differential in material hardness may also affect their ability to correctly hold onto and seal the
tubing.
Pressure ratings for combinations of tube and connector
The pressure rating of a Phastite
®
connection assembly is that of the tube with the highest-pressure rating to which it
can be attached and is presented in Tables 1 to 4. The pressure rating of the tube has been calculated in accordance
with ASME B31.3, Chemical Plant and Petroleum Refinery Piping Standard, assuming maximum diametre, minimum wall
thickness and minimum Ultimate Tensile Strength (UTS).
In the case of an all tube-ended connector, such as a union tee, the properly selected tubing is the limiting factor in
the system. A termination connector may, however, combine a Phastite
®
connector end with another end of different
form, such as male or female pipe thread. Pressure ratings for other ends are determined in accordance with applicable
standards and may, in fact, be lower than the rating for the Phastite
®
tube connector end.
Pressure rating and wall thickness of tubes
Tables 1 to 4 presents the pressure ratings for type 316 Stainless Steel, INCONEL
®
Alloy 625, INCOLOY
®
Alloy 825 and
Super Duplex seamless tubes for temperatures up to 93°C (200°F). These tables also show the minimum and maximum
wall thickness of tubes that shall be used within the scope of the Parker Phastite
®
design for each size of tube connector.
If a user chooses a tube wall thickness outside those recommended in these tables, the user should first consult the
technical department of Parker Instrumentation Products Division.
Derivation of pressure ratings
The working pressure ratings for tubing shall be derived
from stress values and methodologies listed in ASME
B31.3.
Instrument Tubing