Spirax Sarco BM series - Page 8

IM-S21-01 CH Issue 7
8
Fig. 4
KX (DN15 - 25)
Optional
extra
bleed
Optional
extra
bleed
Fig. 3 SBRA
Fig. 5
KX and KY (DN32 - 50)
Strainer
BMRA or
BXRA valve
Small bore
bypass
Fig. 2
Typical bypass
arrangement for
the BMRA and
BXRA valves
3.5 Permanent bleed
BMRA and BXRA valves are normally closed. When used as a cooling control it may be
necessary to create a permanent flow over the sensor. In this case this can be achieved by
installing a small bore bypass around the valve as shown in Figure 2. A 6 mm line will usually
be adequate with the manual valve about one turn open.
SBRA (Figure 3) and KX (DN15 - 25) (Figure 4) valves are available with or without bleed. When
used as a cooling control with the sensor fitted in the cooling liquid line a valve having a bleed
would be required. This bleed hole is now fixed. In other cases, a non bleed valve should be
installed.
With KX and KY valves (DN32 - 50) (Figure 5) again models are available with or without bleed.
Valves with a bleed arrangement have a 3 mm hole between the inlet and outlet. This permanent
bleed arrangement can be sealed by tapping the hole and sealing it off with a 4BA or M4 screw
before the valve is installed.
Optional
extra
bleed