iNStallatioN (continued)
Models 974MSD, 975MSD (continued)
1 . Complete steps 1-6 on page 4 . Be sure to allow 2-3/4 in./
70 mm clearance between back of toilet and wall for MSD
fittings, discharge and vent hose assembly .
2 . Remove discharge spout from top of holding tank by turning
it counterclockwise until it unlocks (see illustration A) and
pulling it out of tank .
3 . Lubricate two small O-rings on discharge fitting with silicone
grease and attach discharge elbow adapter to discharge
fitting . Secure adapter in place with
plastic tie-wrap (see illustration B) .
4 . Lubricate large O-ring on discharge fitting and insert
discharge fitting assembly into holding tank . Rotate it so
that discharge and vent fittings point away from tank (see
illustration C) .
5 . Using hose clamp, attach 1 .5-inch (25 mm) ID discharge
hose over end of elbow adapter . Make sure discharge
hose(s) connect securely to all discharge fittings .
6 . Using hose clamp, attach 5/8-inch
(16 mm) ID vent hose to vent fitting .
Make sure vent hose connects
securely to through-hull vent
fitting .
MariNe SaNitatioN reGUlatioNS
All boats with fixed toilets in U .S . waters and in the waters of some other countries are
required to have an operable, permanently installed marine sanitation device (MSD) .
Series 970 MSD models, when permanently installed in a boat, are holding tank or
Type III systems as defined by the U .S . Coast Guard . Type III systems permit opera-
tion of the toilet without direct discharge of untreated waste after every flush . Type III
systems can be discharged at marina dockside pump-out stations or, if in coastal
waters, a minimum of three miles offshore . Overboard discharge capability must remain
secured while within the three-mile limit . If an overboard discharge pump is activated by
a keyed switch in the toilet compartment, the key must be removed at all times except
when discharge pump is operating and in the process of vessel operation .
Sewage from any source should not be discharged directly into our waters . If
you are interested in learning more about this issue, please visit our website at
www .DometicSanitation .com .
HOLDING
MOUNTING BRACKETS
A
Discharge fitting
B
MSD
DISCHARGE
FITTING
C
TANK
PLUMBING SPECIFICATIONS
Discharge
Vent
Tie-wrap
Vent fitting
Discharge elbow adapter
Hose ID
1 .5 inch / 38 mm
.625 inch / 16 mm
This symbol appears
on the discharge fitting
of MSD models.
5