Accessories; Piping Size / Diffuser; Two-Stage Pressure Reduction; 4.15 Strainer Installation - TLV COS Série Manuel D'utilisation

4.12 Accessories

Always install a shutoff valve and pressure gauge at both the inlet and outlet, and a shutoff valve
in the bypass line. Ball valves, which will not retain condensate, are recommended for inlet and
outlet shutoff valves. The bypass pipe should be at least one half the size of the inlet pipe.
Pressure
Gauge

4.13 Piping Size / Diffuser

If the secondary steam flow velocity is expected to be more than 30 m/s (100 ft/s), install a
diffuser in order to keep the flow velocity below 30 m/s (100 ft/s). If the distance between the
reducing valve and the steam-using equipment is great, a possible drop in pressure should be
taken into consideration when selecting the piping size.
Straight piping:

4.14 Two-stage Pressure Reduction

Two-stage pressure reduction should be performed whenever the pressure cannot be reduced
to the desired level with a single COS/COSR due to operating range limitations, such as when
the reduction ratio is greater than 10:1.
Bypass Valve
Pressure
Gauge
Inlet Shutoff
Valve
COS/COSR
4.15 Strainer Installation (COSR)
A strainer should be installed ahead of the COSR. The strainer should be 60 mesh or finer,
but not so fine that it causes constriction of the flow area and a subsequent pressure drop.
The strainer should be installed horizontally and at 90° to its normal orientation to the pipeline,
in order to prevent condensate accumulation in the screen body (see picture).
Globe Valve
Ball Valve
COS/COSR
10 d or longer upstream
Pressure
Gauge
Shutoff
Valve
̶ 11 ̶
Ball Valve
Diffuser
15 d or longer downstream
Bypass Valve
Shutoff
COSR
Valve
Safety Valve
(Relief Valve)
Pressure
Gauge
Safety Valve
(Relief Valve) Pressure
Gauge
Shutoff
Outlet
Valve