Riva FP, Инструкция по установке и эксплуатации

Страница: 31 / 48

RIVA FP MANUAL 31
14. Piping
All external piping components are to be supplied by the installer. It is very important to use
a Primary Secondary piping scheme when an external circulator will be used. Also, when the
boiler is piped in a primary secondary manner, it is necessary to us the central heating
fl ow
restrictor supplied with the boiler. The fl ow restrictor ensures that there will be enough back
pressure to make the central heating fl ow switch in a low head loss piping system like primary
secondary.
Installation of fl ow restrictor: The fl ow restrictor is installed inside the pipe tail that
attaches to the boiler. Place the fl ow restrictor into the
gasket for the central heating supply pipe tail. Place the
gasket on the pipe tail so the
fl ow restrictor seats into
the pipe tail. Then install the pipe tail onto the boiler.
There are two methods for accomplishing a Primary Secondary piping system. The fi rst is to
use two closely spaced tees for the boiler supply and return. An example is shown below in
Figure 14.1. The run legs should be sized so that there is no excessive head loss on the exter-
nal circulator that is installed. In most circumstances 1 ¼” piping will be the best choice. When
the boiler is piped in this way, the external circulator will not have any hydraulic effect on the
Riva boiler. This is essential to ensure that the
fl ow switch will operate properly.
The second method is a hydraulic separator. Hydraulic separators are available commercially;
however you can also construct your own. An example of a hydraulic separator is given in
Figure 14.2. It is important that the separator be at least 2” in size to ensure proper perfor-
mance.