SeaLand BASIC HOLDING TANK SYSTEM - Manual (Page 3)

3
INSTALLATION
CHOOSING A LOCATION FOR THE BASIC HTS
As a general rule, the HTS should be positioned as low in the hull as possible with all interconnecting hoses or pipes
sloped to permit gravity drainage and prevent potential hose odor permeation.
The holding tank must not be exposed to temperatures above 120°F (45°C). Do not place near heat sources such as
engine manifolds, water heaters, generators, etc.
Be certain to estimate holding tank weight when filled (typical effluent weighs about 9 lbs. per 1 gallon or 1.08 Kg per
liter). Make certain to allow for total filled weight when selecting materials for mounting the tank. Also consider impact
of full tank on vessel trim.
PREPARING A MOUNTING SURFACE
1. Mount tank to surface that supports the entire area of
the tank.
2. If required, fabricate mounting surface and toe blocks
from 13 mm or 19 mm (1/2-inch or 3/4-inch) plywood.
3. Do not mount tank on projections such as screw or
bolt heads, which could puncture the tank.
4. Do not allow holding tank to block free flow of bilge
water.
Mounting surface
made from plywood and
securing straps
AVOIDING HOSE ODOR PERMEATION
• Hose failure due to odor permeation almost
always occurs in hose runs which retain
sewage when the system is not in use.
• Eliminate all unnecessary runs which retain
trapped liquids, if possible.
• Where possible, use rigid PVC pipe in
sections that cannot be arranged to drain.
• Simplify hose layout by removing unnecessary
valves. [For specific installations, some
regulations and standards may require the
installation of a vented loop (anti-siphon
valve), one-way valve or seacock in sewage
discharge piping.]
Simplified plumbing layout
BASIC HTS CONNECTIONS
TankSaver
vacuum relief valve
Vent line/vent filter
Inlet from toilet
Outlet to deck discharge fitting Inspection port
Outlet to
through-hull
discharge fitting
Complicated plumbing layout