Hydraulics B737

[Shaka Zulu]

I was just going through the 737 NG CBT and something came up.
Does the Hydr. B reservoir also have a stackpipe?
I do know that Hydr. A reservoir is equipped with a stackpipe, this in case there is a leak in the Engine Drive Pump Lines there still is about 20% quantity left for the AC Electric Pump to execute all services.
In some questionnaire's though, they state that if there is a leak in the EDP Lines of the Hydr. B reservoir, this tank may empty down to the 0% point. Which made me wonder about the stackpipe...
Does anybody know?

[avioniker]

From SDS 29-10-00-005
Please excuse the grammer. This is from the Maintenance Manual and as everyone knows maintenance personnel must have all of their technical publications written in Simplified English.

Physical Description
The hydraulic system A reservoir has a total volume capacity of 6.8 gallons (25.8 liters).
The hydraulic system B reservoir has a total volume capacity of 10.7 gallons (40.6 liters).
Each reservoir is an airtight metal shell that contains these components: Air pressure port EDP and EMDP supply line port Return line port Drain valve Hydraulic fluid quantity transmitter/indicator.
Functional Description The reservoirs are pressurized by the reservoir pressurization system. The hydraulic system A reservoir has a standpipe for the engine-driven pump (EDP). A port at the bottom of the reservoir supplies fluid to the electric motor-driven pump (EMDP). The reservoir drain valve at the bottom is manually operated. The hydraulic system B reservoir has a standpipe for the EDP and EMDP. A port at the bottom of reservoir supplies fluid to the power transfer unit (PTU) pump. The reservoir drain valve at the bottom is a manually operated valve.
The fill and balance line connects the system B reservoir to the standby reservoir. System B reservoir pressure also pressurizes the standby hydraulic system reservoir. See the standby hydraulic system section for more information for the standby hydraulic system reservoir. (SECTION 29-22) The quantity indicator shows O for empty, RFL for refill, and F for full. See the hydraulic indicating system section for more information for the hydraulic fluid quantity transmitter/indicator. (SECTION 29-30) This table shows nominal quantities at different levels in the reservoirs.

RESERVOIRS QUANTITY (GAL/L) QUANTITY SHOWN ON CENTER DISPLAY UNIT

A
FULL LEVEL 5.7 / 21.6 100%
REFILL 4.7 / 17.7 76%
EDP STANDPIPE 2.3 / 8.5 20%
OVERFILL MORE THAN 5.7 / 21.6 101-106%

B
FULL LEVEL 8.2 / 31.1 100%
REFILL 6.9 / 26.0 76%
FILL & BALANCE 6.6 / 25.1 72%
EDP/EMDP STANDPIPE 1.3 / 4.9 0%
OVERFILL MORE THAN 8.2 / 31.1 101-106%

[Shaka Zulu]

So: to conclude, the last hydr fluid left in sys B is for PTU operation.
I've got it, thanx!