Pentair FLECK 3150 NXT Installer Manual page 41

• should the flexible piping connection be installed in vertical position, instead of
compensating the elongation, it will create additional stresses on the valve & tank
assembly. Therefore this is to be avoided;
• the flexible piping connection must be also being installed stretched, avoiding
excessive length. For instance 20 – 40 cm is enough;
• excessively long and non-stretched flexible piping connection will create stresses
on the valve and tank assembly when the system is pressurized, as illustrated in
the below picture: on the left the assembly when the system is unpressurised, on
the right the flexible piping connection when put under pressure tends to lift up
the valve when stretching up. This configuration is even more dramatic when using
semi-flexible piping;
• failure to provide enough vertical compensation may lead to different kinds of
damage, either on the valve thread which connect to the tank, or on the female
thread connection of the tank that connect to the valve. In some cases, damage
may also be seen on the valve inlet and outlet connections;
• in any case, any failure caused by improper installations and/or piping connections
may void the warranty of Pentair products;
• in the same way, using lubricant* [}Page 41] on the valve thread is not allowed
and will void the warranty for the valve and tank. Indeed using lubricant there will
cause the valve to be over-torqued, which may lead to valve thread or tank thread
damage even if the connection to piping has been done following the above
procedure.
*Note: Use of petroleum-based grease and mineral based lubricant is totally forbidden,
not only on the valve thread, since plastics (especially Noryl) will highly suffer from
contact with this type of grease, leading into structural damage hence to potential
failures.
Ref. MKT-IM-010 / C - 18.10.2019
Installer manual Fleck 3150 NXT/NXT2 - Installation
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