Pentair Riva Viridion 8L Handbuch Seite 11

4.2.2. Water supply line
The connections should be hand tightened using PTFE (plumber's tape) on the threads if using the threaded connection type.
In case of heat welding (metal type connection), the connections should not be made to the valve when soldering.
NOTE
See chapter 3.1. Technical specifications, page 7 to identify the connections.
When pressurized, any composite tank will expand both vertically and circumferential. In order to compensate the vertical
expansion, the piping connections to the valve must be flexible enough to avoid overstress on the valve and tank.
In addition, the valve and tank should not be supporting any part of the piping weight. This is hence compulsory to have the piping
fixed to a rigid structure (e.g. frame, skid, wall...) so that the weight of it is not applying any stress on the valve and tank.
• The diagrams above illustrate how the flexible piping connection should be mounted;
• in order to adequately compensate the tank elongation the flexible tubes must be installed horizontally;
• 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 be 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
connects to the tank, or on the female thread connection of the tank that connects 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 installation and/or piping connections may void the warranty of Pentair
products;
• in the same way, using lubricant* 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-UG-044 / A - 02.06.2020
User Guide Riva Viridion
200 mm flexible
Support to the wall
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