172-65613A-03 (DR8-3P/DR8-3EP/DR8-6P/DR8-6EP) 11 Jun 2020
10
7. Accessories
Always install a bypass line. At the inlet and outlet, install a pressure gauge
and a shut-off valve. Ball valves, which will not retain condensate, are
recommended for inlet/outlet shut-off valves. The nominal pipe size for the
bypass line should be
1
/
2
or greater of the primary pipe size.
DR8
Pressure
Gauge
Inlet
Valve
Safety Valve
(Relief Valve)
Primary
Side
Secondary
Side
Ball
Valve
Bypass Valve
Pressure
Gauge
Outlet
Valve
Ball
Valve
Steam Trap
8. Blowdown (Installing the bypass valve)
Before installing the DR8 or supplying steam to the DR8, be sure to blow down
all piping thoroughly. Installing the bypass valve makes blowdown easier.
Blowdown is especially important for newly installed piping or after the system
has been shut down for a long period of time. This will reduce operation failure
caused by condensate or foreign matter. The bypass valve should not be
opened too quickly. If a safety valve (or relief valve) is installed, perform
blowdown staying clear of pressurized blow-out.
If condensate accumulates while the inlet valve is closed, install a steam trap
that has a sufficient discharge capacity considering the initial condensate
discharge amount.
To perform blowdown, close the inlet valve (A) first, then the outlet valve (B), and
open the bypass valve (C). Do not open valves too quickly.
Pressure
Gauge
Steam
Trap
Steam
Trap
Safety (Relief)
Valve
DR-8
Inlet Valve
(A)
Bypass Valve
(C)
Outlet Valve
(B)
Pressure
Gauge
Primary
Side
Secondary
Side
