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For I.D. from 14" to 36", the No Loss Cap include an 12" inner wall that attaches
to the chimney flue using a standard inner V-Band (BSI) (See JOINT ASSEMBLY
Section). The outer wall is made of different combinations of single wall DCL Length
that has a diameter 2" larger that the flue flue diameter to have the right height for
each diameter (4 x I.D.). The DCL section must be built up on an Anchor Plate Plate
(AP) and a framework (by others) attached to the building, overlapping the inner flue
by 6". See Figure 71b.
Figure 71b and c - No Loss Cap (NLC) installed for I.D. from 14" to 36"
DRAINING SECTIONS
If rain is to enter the Chimney, install a Drain Length (DL) at least 5 pipe diameters
below the chimney outlet, but above any Tee or Elbows. A Drain Tee Cap (DTC) at the
base of a vertical run can also be used. If the system is under pressure, use a "P" trap
at least the same height of the maximum pressure of the system.
DRAIN LENGTH (DL)
A Drain Length (DL) is used to drain water on vertical runs. It is an 18" pipe length with
provision to drain rain or condensate from the chimney. The pipe flue is equipped with
an annular catch gutter wall and a 1" (25) NPT nipple extending through the casing for
attachment of drain piping. See Figure 72. The drain piping should include a water leg
of a height at least equal to the maximum expected operating pressure at the appliance
outlet to avoid allowing flue gases to vent through the drain. Drain Length should be
installed indoors to prevent freezing.
Figure 72 - Drain Length (DL).
HORIZONTAL LENGTH (HDL)
The Horizontal Drain Length (HDL) has the same function and dimensions as the Drain
Length (DL), but used on horizontal run and has a dam just below the NPT Drain instead
of a gutter. The dam directs the water through the drain See Figure 73.
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Figure 73 - Horizontal Length (HDL)
NOZZLE LENGTH (NL)
The Nozzle Length NL is used when there is a need for test port. Same size as the Drain
Length (DL). See Figure 74.
Figure 74 - Nozzel Length (NL)
RELIEF VALVE FOR EXCESSIVE PRESSURE
RELIEF VALVE (RV)
The Relief Valve (RV) is designed for installation in the exhaust system of stationary
Internal Combustion Engines (Diesel Engine). It's function is to protect engine exhaust
components from damage due to engine exhaust explosions (backfire). It is recommended
to add a Relief Valve on each Diesel Engine Exhaust System and should be installed as
close to the engine exhaust outlet as is safely possible to prevent damage to system.
The RV is intended to help control the venting of pressure which may occur during an
exhaust system backfire. Engines have the potential to inject unburned fuel into an
exhaust system during start up or due to an engine malfunction.
This unburned fuel creates a condition where a backfire could occur. The RV will help
prevent damage to other parts such as Flex Connectors, Silencers, Catalytic Converters,
Convoluted Bellows and Heat Recovery Equipment. It can also limit exhaust back
pressure on the engine.
Further precedence for use of the Relief Valves can be found in NFPA 37, "Standards for
the Installation and Use of Stationary Combustion Engines and Gas Turbines".
MAINTENANCE OF THE RELIEF VALVE IF USED OUTDOORS: It is RECOMMENDED to
apply an exterior grade high heat paint to the Guide Plate, Valve Seat, Valve Plate, and
Flange Adapter to ensure maximum corrosion resistance. (Ex. Rustoleum V2100 series
High Heat Industrial Aerosol).
CAUTION: This device is designed to relieve excessive pressure (30" w.c. with standard
springs) in the case of an engine malfunction for the sole purpose of protecting the
physical integrity of the exhaust system and related parts. If such malfunction occurs,
the device will release hot gases, sparks and/or flames into the immediate vicinity
of the RV. As such, this device should never be installed where human contact with
any such release is possible, or near flammables or combustibles like gas canes,
oils, or other such materials.
The Relief Valve (RV) consists of a spring loaded disk valve mounted on ANSI flange.
See Figure 75a.
Additional flange gasket and bolt set (supplied by others) by others) should be use for
the connection to our 125/150 lb ANSI Flange Adaptor (FA). The gasket and bolts are
typically sold by pipe, valve and fittings houses as an "NBG" (Nut, Bolt Gasket Kit) set.
The valve is factory calibrated to open at 27 in. of water column. The calibration nuts
must not be changed or the valve may not function correctly. If additional tension is
required due to normal operating pressures exceeding 27" of w.c., additional auxiliary
springs may obtained by contacting DuraVent.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
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