User Guide

ManaBloc Systems
24
PG-PF 724998 0320 PureFlow System
Supply and Distribution Line Sizing
The best water and energy savings of
a ManaBloc system are realized when
distribution lines are sized according to
the 󶈵xture demand and the length of the
individual line. Viega recommends the
following tube sizing.
Typical supply line size:
■ ¾" up to 2½ baths
■ 1" up to 4½ baths
Typical distribution line size:
■ ⅜" up to 2½ GPM 󶈵xture 󶈶ow
requirement (lavs, toilets, bidets, bar
sinks, kitchen sinks, dishwashers)
■ ½" up to 4 GPM 󶈵xture 󶈶ow
requirement (hose bibbs, tubs,
showers, washing machines, whirlpool
baths, soaking tubs, etc.)
Consult the 󶈵xture manufacturer’s
literature to determine the actual 󶈵ll rate
and residual pressure requirements for
distribution line size. In addition, con󶈵rm
with local Authority Having Jurisdiction
(AHJ) for acceptable PEX tubing size.
Note: If a hose bibb is primarily for
irrigation purposes, it should be supplied
from the main service line prior to the
ManaBloc.
A Viega PureFlow Press and PureFlow
Crimp ManaBloc come with ½" ports
that are designed to 󶈵t both ⅜" and ½"
PureFlow port adapters.
Water Heater Placement
The Viega ManaBloc should be as
close as possible to the water heater to
minimize extra water from being stored in
the larger hot water supply lines between
the ManaBloc and water heater.
The longer the hot water supply line is,
the greater the volume of water needed
to purge through that line and faucet
before hot water is available. This creates
water waste and longer hot water delivery
times (see “ManaBloc Location” on page
25 for more information).
Distribution Line Sizing to Fixture
Proper water distribution line sizing
to each 󶈵xture is crucial for overall
system performance. If you oversize a
distribution line to a 󶈵xture (½" PEX line
supplying a sink instead of a ⅜" PEX line)
you are essentially doubling the volume
of water being stored in that line. It can
take roughly twice as long to purge an
oversized line compared to a properly
sized line.
The 󶈵xture is what dictates water 󶈶ow
(federally mandated, governed by code).
The tubing applies a friction loss dictated
by its size and length. Therefore, as long
as you do not undersize a distribution line
or run it excessive distances (60 feet or
greater), the system will perform properly,
maintaining su󶈷cient pressure and 󶈶ow.