October 2017
RiverPro and RioPro ADCP Guide
Page 52
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Transducer Head Assembly Replacement
Always replace the transducer head prior to replacing the end-cap.
To install the transducer had assembly:
1. Stand the RiverPro/RioPro housing on its end.
2. Inspect, clean, and lubricate the O-ring on the housing (see
O-ring Inspection and Replacement
).
Install the O-rings.
TRDI recommends using new O-rings when preparing for a deployment.
Apply a very thin coat of silicone lube on the O-ring. Using too much silicone lube on the O-
ring can be more harmful than using no O-ring lube at all.
3. Gently lower the transducer head/electronics assembly into the housing, aligning the mating
holes. When mating the housing with the transducer head flange try to apply equal pressure to all
parts of the O-ring. Make sure the face O-ring remains in the retaining groove.
Check that no wires or any other object is pinched between the transducer head assembly
and the housing. Use rubber bands to hold the wiring in place as necessary. If the O-ring is
not in the groove or if a wire or other object is pinched, the RiverPro/RioPro will flood.
4. Examine the transducer assembly bolts and washers for corrosion; replace if necessary. Use Fig-
ure 17 and Figure 18 for parts identification. All hardware items are needed to seal the
RiverPro/RioPro properly.
5. Install all four sets of hardware until “finger tight.”
6. Tighten the bolts in small increments until the split washer flattens out, and then tighten each
bolt ¼ turn more to compress the face seal O-ring evenly. Tighten the bolts to the recommended
torque value shown in Table 4.
Table 4.
Torque Settings
Bolt Size
Torque (pound-inches)
Torque (Newton-meters)
M5X0.8
4.5
0.51
M6X1.0
10.62
1.20
M8X1.25
25.2
2.85
Apply equal pressure to the O-ring as the bolts are tightened. If one bolt is tightened more
than the others, the O-ring can become pinched or torn. A damaged O-ring will cause the
system to flood.
Do not over tighten the bolts that hold the transducer, housing, and end cap together. The
plastic housing can crack or break if tightened too much. On the other hand, leaving the bolts
too loose can cause the system to flood. Tighten the bolts to the recommended torque value
shown in Table 4.
