Pipe: Type PSM SDR-35, ASTM D3034, or Type PS-46,
ASTM F789, or ASTM F794 (ribbed or closed profile, smooth interior)
or ASTM F949 (corrugated, smooth interior). Use ASTM F679 for over
15 inches in diameter. Depth of construction of ASTM D3034 pipe shall
be limited to 15 feet; deeper sewers shall be SDR 21.
Cement-lined ductile iron pipe (DICL): ductile iron
pipe conforming to ANSI A21.51 or AWWA C151 for the material class
or pressure designated, and ANSI A21.50 or AWWA C150 for wall thickness.
Ductile iron in accordance with the standard
specification set forth in the ANSI A21.10 or AWWA C110. All fittings
shall be minimum Class 250 with cement lining and joints as required
for pipe restraint.
Flexible pipe coupling: made of flexible elastomeric
PVC with two Series 300 stainless steel adjustable clamps. See Detail
Drawings 9, 11, 12, 31, 32, 33, 34, 35, and 37 in Appendix SB.
Joints: push-on with elastomeric gasket, ASTM D 3212;
and ASTM F 477 for gasket specification. Rigid pipe joints, including
glued or solvent welded joints, will not be permitted for buried service.
Material. Polyethylene pipe shall conform to ASTM D-1248 and D-3350
for Type III Grade P34, Category 5, and Plastic Pipe Institute Material
Designation PE-3408. Pipe shall be SDR-11 or approved equal.
Joints. Pipes shall be joined by thermal butt-fusion in accordance
with ASTM D-2657 and the pipe manufacturer's recommendations.
Termination to pump basins, valves and fittings shall be flange assemblies.
The pipe adjacent to these joints must be rigidly supported for a
distance of one foot beyond the flange assembly.
Fittings. Fittings shall conform to all applicable ASTM D3261 (HDPE)
and other ASTM specifications. Fittings shall have plain ends for
thermal butt-fused joining. Fittings shall have the same type, grade
and class of PE compound. Mechanical compression fittings shall be
used only when joining to different piping materials.
Pipe plug materials: designed for permanent installation
and removable. Obtain plugs for various types of pipe used from respective
pipe manufacturers.
Molded PVC solvent weld 45° saddle wye, with a captive rubber
O-ring flange gasket and stainless steel strap(s) with stainless steel
bolts for attachment to the lateral sewers.
Sewer service check valve shall be installed in a
horizontal portion of the sewer service line and shall prevent the
reverse flow of wastewater into the structure.
The check valve shall be supplied in a kit from one
manufacturer consisting of a valve body, disk, disk seat and upper
collar. It shall comply with CSA B181-4, and the plastic materials
shall conform to ASTM D1784, cell classification 12454-B and NSF 14.
The check valve shall include an access sleeve that
is a pipe opening through which access is gained to the disk or valve
seat. The access sleeve shall be cut to length in the field and attached
to the socket on the top of the valve body.
The collar, insert pipe and disk assembly shall be
designed to fit inside the access sleeve, the removable assembly shall
consist of a length of insert pipe permanently attached to the access
collar on the top and a disk assembly on the bottom. It is then removed
vertically from the access sleeve, the attached disk assembly is also
removed allowing above grade repair. The internal lifting device is
self-aligning, self-seating and provided with an alignment indicator
located with 12 inches of the upper access opening.
The check valve shall be installed on horizontal drainage
systems with uniform slope. The access sleeve shall terminate above
grade and shall have a maximum length of 12 feet.
Cement-lined ductile iron pipe (DICL): ductile iron
pipe conforming to ANSI A21.51 or AWWA C151 for the material class
or pressure designated, and ANSI A21.50 or AWWA C150 for wall thickness.
Fittings: ductile or gray iron in accordance with
ANSI A21.10 or AWWA Specification C110. All fittings shall be minimum
Class 250 with cement lining and joints as required for pipe restraint.
Joints: push-on type or mechanical joint type in accordance
with ANSI A21.11 or AWWA C111 Specifications. Restrained joint pipe
shall be used for pressure applications.
Restrained joint pipe, manufactured of ductile
iron per ANSI/AWWA C151/A21.51, with restrained push-on joints. Restraint
system shall be designed to allow disassembly of joints, if required.
See Detail Drawing 26.
Restrained joint pipe, manufactured of ductile
iron per ANSI/AWWA C151/A21.51, with rigid restrained mechanical joints.
Restraint system shall be designed to allow disassembly of joints,
if required. See Detail Drawing 26.
Tie rods providing full joint restraint and
extending to the adjacent fitting or joint, and beyond to each successive
fitting or joint, to provide adequate restrained length in accordance
with the Standard Details, and as approved by the National Board of
Fire Underwriters No 124, "Standard for Outside Protection." All rods,
clamps, nuts, and washers utilized for anchorage shall be stainless
steel.
The solid foil core shall be encased between a one-hundred-percent
virgin polyolefin pigmented film and a clear protective film that
allows a full view of the foil to insure continuity. The solid core
provides for detectability utilizing either the inductive or conductive
modes using a pipe and cable locator.
Tape shall be installed at a depth between 12 and 18 inches below
the finish surface for all nonmetallic pipeline materials unless the
force mains are installed by the directional boring method.
Mechanical joint coupling: consisting of one cylindrical steel middle ring, two follower rings, two resilient gaskets, and a set of steel trackhead bolts. Acceptable manufacturer(s) are listed in § 150-13 of this chapter.
Tracer wire shall be #12 AWG CHS-CCS high-strength copper clad steel
conductor, insulated with a 30 mil, high-density, high-molecular-weight
polyethylene (HDPE) and rated for direct burial use at 30 volts. Insulation
color shall meet the APEAZ color code standard for identification
of buried utilities. For sewer lines, the color is green. The tracer
wire shall be attached to the force main at five-foot intervals with
plastic zip ties. (Attaching the wire with tape is expressly prohibited.)
Install a tracer wire test station at no greater interval than 300
feet without a tracer wire magnetized tracer box. The boxes shall
have a cast iron cover and shall be extended to grade. Use boxes rated
for traffic loads in roadway installations. For tracer boxes located
in sidewalks and driveways, use a tracer box that has the appropriate
top section for concrete or driveway applications. The tracer wires
shall terminate in the tracer boxes. The boxes shall have covers with
"sewer" designated.
All splices of the tracer wire underground shall be made with connectors
manufactured for this type of service. At tees, the three wires shall
be joined using a single three-way lockable connector. At crosses,
the four wires shall be joined using a four-way connector. Connectors
shall have dielectric silicon filled to seal out moisture and corrosion
and shall be installed in a manner so as to prevent any uninsulated
wires to be exposed. Nonlocking friction-fit, twist-on or taped connectors
are prohibited.
General. Manholes and other concrete structures shall
conform to the requirements in ASTM C478, latest edition, except as
indicated below. Design and dimensions of base, tapered and straight
riser sections, top section and pipe connections shall be as indicated
on the Standard Details.
Concrete: composition and compressive strength conforming
to ASTM C478 except use Type II or Type III cement in manhole components
and increase compressive strength to 4,500 psi (at 28 days) in precast
bases.
Manhole bases shall be precast with factory precast
flow channels, unless otherwise approved by LASA. The invert channels
shall be smooth and semicircular in shape conforming to the inside
of the adjacent sewer section. Changes in direction of flow shall
be with a smooth curve of as large a radius as the size of the manhole
will permit. Changes in size and grade of the channels shall be made
gradually and evenly. The floor of the manhole outside the channels
shall be smooth and shall slope towards the channels at 1/2 inch per
foot. The use of cast-in-place bases or channels may be permitted
by special exception from LASA for specific manholes; the bases and
channels shall conform to the requirements of this section.
Precast top sections: design and dimensions as required
by conditions of materials and construction as specified previously
except additional and differing requirements as follows:
Frame hold-down bolt inserts. Factory cast in top
section, four three-fourths-inch slotted, moveable, polypropylene-coated,
threaded inserts, of three inches depth, to accommodate manhole frame
hold-down bolts. Inserts shall be designed for an ultimate load in
tension of 12,500 pounds. Inserts shall be factory plugged for shipping.
Coordinate insert location with frame manufacturer to assure proper
location in top sections.
Eccentric cone tops: manufacture to minimum wall thickness
shown on Details and with same area of circumferential steel reinforcement
as riser sections.
Preformed butyl rubber sealing compound: Manhole component joints shall be factory formed for self-centering, concrete-to-concrete-bearing, employing preformed butyl rubber base, sealing compound, conforming to Fed. Spec. SS-S210A, Type 1, Rope Form, shipped protected in a removable two-piece wrapper. Size cross-section of rope form to provide squeeze-out of material around entire interior and exterior circumference when joint is completed. Provide two strips of material, one around the interior and one around the exterior circumference of the joint. Products not containing butyl rubber are not acceptable. Acceptable manufacturers are listed in § 150-13 of this chapter. See Detail Drawings 1, 2, 3, 4, 5, 6, 7, 13A, and 13B.
Grout: Nonshrink, nonmetallic, ready-mix requiring only the addition of water. Acceptable manufacturers are listed in § 150-13 of this chapter. See Detail Drawings 1, 3, 4, 5, 6, 7, 9, 10, 11, 13A, 13B, 14, 15, 36, 37, and 38.
Manhole steps: factory installed in manhole components, prealigned vertically, spaced on twelve-inch centers, with a minimum clear step width of 10 1/2 inches. The rungs shall have a drop front to prevent side slippage. The first step shall not be more than 24 inches from the top of the manhole. Steps to be manufactured of aluminum or polypropylene as designated. Manhole steps shall be cast-in-place or inserted into polypropylene inserts. Acceptable manufacturers are listed in § 150-13.
Reinforced plastic step: composed of a one-half-inch
Grade 60, ASTM A615, deformed steel reinforcing bar, completely encapsulated
in copolymer polypropylene compound conforming to ASTM D4101.
Precast or LASA-approved plastic grade rings: leveling
and adjusting units of thickness required to the minimize number of
rings (maximum of 2), and of materials and construction as specified
previously. Factory cast or LASA-approved plastic type grade rings
shall have hold-down bolt holes matching location of same in manhole
frame. Design must provide for full bearing of manhole frame.
Manhole frame and cover: gray iron castings conforming
to ASTM A48, Class No. 30, designed for AASHTO Highway Loading Class
HS-25. Provide castings of uniform quality, free from blowholes, porosity,
hard spots, shrinkage distortion, or other defects.
Identification: Cast the word "LASA" integrally in
two-inch-size raised letters on all covers, except those on sampling
manholes and manholes on private lines; these covers shall read "SEWER."
Watertight manhole frame and bolted lid: gray
iron castings conforming to previously specified requirements for
manhole frame and cover shall have concealed pickholes, furnished
with four one-inch anchor holes.
Manhole insert. Designed to fit the manhole frame rim, shall be manufactured from high-density polyethylene copolymer material meeting requirements of ASTM D1248, Class A, Category 5, Type III. Insert shall be 1/8 inch thick minimum and shall have two one-fourth-inch vent holes located 180° apart, 1 1/2 inches from the top. Insert shall be made no less than eight inches deep to allow the manhole cover to swing free when being removed. Insert shall have a close cell neoprene gasket with adhesive backing, installed on the insert rim by the manufacturer, and shall have a corrosion-resistant nylon lifting strap for removal and reinstallation. Manhole cover shall sit flush with the adjacent grade when insert is in place. Acceptable manufacturers are listed in § 150-13 of this chapter. See Detail Drawings 4 and 5.
Interior plastic liner: Air-release manholes, manholes to which force mains discharge and the next five manholes downstream, and other manholes as required by LASA, shall be fitted with thermoplastic liners. Liners shall be semirigid PVC formed to fit manhole contours. Acceptable manufacturers are listed in § 150-13 of this chapter.
Protection between the lined manhole and the frame
and cover shall be obtained by installing either a PVC telescoping
connector, of the same manufacturer as the liner, or a one-piece liner
cover manufactured from semirigid PVC.
Prepare surfaces to be coated in accordance with the
written instructions of the coating manufacturer, including cleaning,
sandblasting or acid etching as necessary.
Interior corrosion-resistant coatings (existing manholes
or concrete structures): Where interior corrosion-resistant coatings
are required by the Authority, prepare manhole surfaces to be coated
in accordance with the written instructions of the coating manufacturer,
including cleaning, sandblasting, or acid etching as necessary.
Pipe openings: custom preformed during manufacturing
in each base and riser section requiring such, to accommodate type
of pipe and pipe opening seal provided.
Pipe opening seals - mechanical pipe seals (for existing
manholes): Modular mechanical type, consisting of interlocking synthetic
rubber links shaped to continuously fill the annular space between
the pipe and wall opening. Links shall be connected with stainless
steel bolts to form a continuous belt.
Pipe opening seals - expandable sleeve and boot seals
(for new or existing manholes) shall consist of a stainless steel
expandable sleeve, rubber boot and stainless steel take-up ring installed
to manufacturer's specifications. Pipe opening seals shall conform
to ASTM C923.
Drop manholes: construct in accordance with type indicated
in details on drawings. Use same type pipe and fittings in drop connection
as used in sewer line from which drop connection is made.
Sewage air release valve: designed to automatically
release air, gas, or vapor under pressure during system operation.
Valve design shall feature short body and float stem components so
that the operating mechanism is kept free from contact with sewage
during operation. Valve construction as follows:
Valve body and cover: ASTM A126 Class B cast-iron
body and cover with a threaded inlet connection of the size shown
on the Drawings and with a one-half-inch NPT outlet connection near
the top and one-inch NPT port near the bottom to permit the installation
of flushing attachments.
Valve shall have an 18-8 stainless steel float and
a replaceable seat of Buna-N or other suitable material. Internal
leakage mechanism shall be 18-8 stainless steel. Plastic or bronze
linkage is not acceptable. The linkage mechanism shall be capable
of being removed from the cover without disassembly of the mechanism.
Valves shall have three-sixteenth-inch diameter stainless steel orifice
for working pressures up to 150 psi.
Provide flushing attachments to include one-half-inch
flushing valve, one-inch blow off valve, five feet of rubber hose
and quick-disconnect couplings.
Sewage air and vacuum valves: designed to automatically
exhaust large quantities of air during the filling of a system and
to allow air to reenter the system during draining or when a vacuum
(negative pressure) occurs. Valve design shall feature short body
and float stem components so that the operating mechanism is kept
free from contact with sewage during operation. Valve construction
is as follows:
Air and vacuum valves shall be of the size listed
in the schedule or shown on plans with threaded inlet and outlet to
three-inch size. Body and cover shall be ASTM A126 Class B cast iron.
Valve body shall be tapped one-half-inch NPT near the top and one-inch
NPT near the bottom to permit the installation of flushing attachments
and have a two-inch NPT plugged port near the base to facilitate cleanout
of large solids.
Valves shall have a 316 stainless steel plug and removable
316 stainless steel seat ring in a ductile iron cage. The plug shall
contain a renewable resilient O-ring seat of Buna-N or other suitable
material retained in a dovetail groove. There shall be a single float
ball of 18-8 stainless steel, attached to a stainless steel stem by
means of a universal connection.
Provide flushing attachments to include one-half-inch
flushing valve, one-inch blow off valve, five feet of rubber hose
and quick-disconnect couplings.
Sewage combination air valves: consisting of an air-release
valve and an air and vacuum valve factory piped into a compact assembly.
The combination assembly shall automatically release air, gas or vapor
under system operating pressure and shall also allow air to reenter
the system during draining or when a vacuum (negative pressure) occurs.
Combination valve designs shall feature short bodies and float stem
components so that the operating mechanisms are kept free from contact
with sewage during operation. Valve construction as follows:
Sewage combination air valve shall have a large orifice
for the air and vacuum function and a small orifice for the air-release
function valve contained in a single body. The air and vacuum orifice
shall be the same size as the nominal size of the combination air
valve.
The valve body shall have a threaded inlet and outlet
to three-inch size and ANSI B16.1 Class 125 flanged inlet and threaded
outlet in larger sizes. Body and cover shall be ASTM A 126 Class B
cast iron. Valve body shall be tapped two-inch NPT near the bottom
to permit cleanout of large debris. Additional one-inch and one-half-inch
NPT taps shall be provided for the installation of flushing attachments.
Valves shall have a 316 stainless steel plug and removable
316 stainless steel seat ring in a ductile iron cage. The plug shall
contain a renewable resilient O-ring of Buna-N or other suitable material
retained in a dovetail groove connection. All other internal metal
components shall be stainless steel. Bronze or plastic components
are not acceptable. The air release orifice shall be stainless steel
orifice for working pressures up to 150 psi.
Provide flushing attachments to include one-half-inch
flushing valve, one-inch blow off valve, five feet of rubber hose
and quick-disconnect couplings.
Steel casing pipe diameter: as indicated on the drawings,
or if not indicated shall be at least six inches larger than the combined
outside diameter of the pipe bells, or as required by the owner of
the right-of-way or entity issuing the permit.
Casing spacers: band and risers constructed of 304
stainless steel, or HDPE, with a 90 mil thick PVC or neoprene liner.
Runners shall be constructed of UHMW polymer. All fasteners shall
be stainless steel. See Detail Drawings 24 and 25.
Casing end seals: by same manufacturer as spacers,
wraparound type, fabricated from one-eighth-inch synthetic rubber.
Seals shall be secured to casing utilizing 304 stainless steel straps
with worm gear mechanism. See Detail Drawings 24 and 25.
Final restoration over trenches and at manhole locations
as indicated on the Standard Details.
Construction of new pump stations and alterations,
additions, or modifications to existing pump stations shall be in
accordance with the Authority's requirements. The developer shall
acquire the necessary drawings and specifications from the Authority
prior to commencing with design of a pump station.
The individual pump station shall be a factory-built and tested wetwell/drywell
grinder pump station consisting of a grinder pump suitable mounted
in a basin constructed of high density polyethylene (HDPE) for simplex
stations. NEMA 6P electrical quick-disconnect, pump removal system,
stainless steel discharge assembly/shut-off valve, anti-siphon valve/check
valve, each assembled in the basin, electrical alarm panel and all
necessary internal wiring and controls. All components and materials
shall be in accordance with the Authority Rules and Regulations. The
individual grinder pump system shall be manufactured by Environment
One or Authority-approved equal. The normal grinder pump unit shall
be a Model DH071 or any update or modification model thereto or Authority-approved
equal. The developer's (or homeowner's) engineer shall review
the hydraulic requirements of the application and confirm that the
use of the normally specified pump is acceptable or shall specify
an alternative pump model that would be acceptable to the Authority.
For each individual grinder pump unit installed in a development within
the LASA service area, the developer shall provide a lump-sum cash
payment to LASA to cover the cost of inspection; which fee shall be
established by resolution of the LASA Board.
The pump shall be a custom designed, integral vertical rotor, motor
driven solids handling pump of the progressing cavity type with a
single mechanical seal. Double radial O-ring seals are required at
all casting joints to minimize corrosion and create a protective barrier.
All pump castings shall be cast iron, fully epoxy coated to 8-10 mil
nominal dry thickness wet applied. The rotor shall be through-hardened,
highly polished, precipitation hardened stainless steel. The stator
shall be a specifically compounded ethylene propylene synthetic elastomer.
This material shall be suitable for domestic wastewater service. Its
physical properties shall include high tear and abrasion resistance,
grease resistance, water and detergent resistance, temperature stability,
excellent aging properties, and outstanding wear resistance.
The pump shall be capable of delivering 15 GPM against rated total
dynamic head of 0 feet (0 PSIG), 11 GPM against a rated total dynamic
head of 92 feet (40 psig) and 7.8 GPM against a rated total dynamic
head of 185 feet (80 PSIG). The pump must be capable of operating
at negative total dynamic head without overloading the motor; under
no conditions shall in-line piping or valving be allowed to create
a false apparent head.
The grinder shall be placed immediately below the pumping elements
and shall be direct driven by a single, one-piece motor shaft. The
grinder impeller (cutter wheel) assembly shall be securely fastened
to the pump motor shaft by means of a threaded connection attaching
the grinder impeller to the motor shaft. The grinder impeller shall
be one-piece, 4140 cutter wheel of the rotating type with inductively
hardened cutter teeth. The cutter teeth shall be inductively hardened
to Rockwell 50-60c for abrasion resistance. The shredder ring shall
be of the stationary type and the material shall be white cast iron.
The teeth shall be ground into the material to achieve effective grinder.
The shredder ring shall have a staggered tooth pattern with only one
edge engaged at a time, maximizing the cutting torque.
The assembly shall be dynamically balanced and operate without
objectionable noise or vibration over the entire range of recommended
operating pressures. The grinder shall be constructed so as to minimize
clogging and jamming under all normal operating conditions including
starting. Sufficient vortex action shall be created to scour the tank
free of deposits or sludge banks which would impact the operation
of the pump.
The grinder shall be capable of reducing all components in normal
domestic sewage; including a reasonable amount of foreign objects
such as paper, wood, plastic, glass, wipes, rubber and the like, to
finely divided particles which will pass freely through the passages
of the pump and the one-and-one-fourth-inch diameter stainless steel
discharge piping.
As a maximum, the motor shall be a one HP, 1,725 RPM, 240 volt 60
Hertz, one-phase capacity start, ball bearing air-cooled induction
type with Class F installation, low starting current not to exceed
30 amperes and high starting torque of 8.4 foot pounds. The motor
shall be press-fit into the casting for better heat transfer and longer
winding life. Inherent protection against running overloads or locked
rotor conditions for the pump motor shall be provided by the use of
an automatic-reset, integral thermal overload protector incorporated
into the motor. The motor protector combination shall be listed by
Underwriters Laboratories, Inc., for the application. The wet portion
of the motor armature must be 300 Series stainless steel.
The pump/core shall be provided with a mechanical shaft seal to prevent
leakage between the motor and pump. The seal shall have a stationary
ceramic seat and carbon rotating surface with faces precision lapped
and held in position by a stainless steel spring.
The tank shall be a wetwell/drywell design made of high density polyethylene,
with a grade selected to provide the necessary environmental stress
cracking resistance. Corrugated sections are to be made of a double
wall construction with the internal wall being generally smooth to
promote scouring. The corrugations of the outside wall are to be minimum
amplitude of 1 1/2 inches to provide necessary transverse stiffness.
Any incidental sections of a single wall construction are to be 0.250
inch thick (minimum). All seams created during tank construction are
to be thermally welded and factory tested for leak tightness. The
tank wall and bottom must withstand the pressure exerted by saturated
soil loading at maximum burial depth. All station components must
function normally when exposed to 150% of the maximum external soil
and hydrostatic pressure.
The drywell accessway shall be an internal extension of the
wetwell assembly and shall include a lockable cover assembly providing
low profile mounting and watertight capacity. The cover shall be high-density
polyethylene, green in color, with a load rating of 150 pounds per
square foot. The accessway designed and construction shall enable
field adjustment of the station height in increments of three inches
or less without the use of any adhesives or sealants requiring cure
time before installation can be completed. The station shall have
necessary penetrations molded in and factory sealed. To ensure a leak-free
installation, no field penetrations will be acceptable.
All discharge piping shall be constructed of 304 stainless steel.
The discharge shall terminate outside the accessway bulkhead with
a stainless steel, one-and-one-fourth-inch female NPT fitting. The
discharge piping shall include a stainless steel ball valve rated
for 235 psi WOG, PVC. The bulkhead penetration shall be factory installed
and warranted by the manufacturer to be watertight.
The accessway shall include a single NEMA 6P electrical quick-disconnect
for all power and control functions, factory installed with accessway
penetrations warranted by the manufacturer to be watertight. The quick
disconnect will be supplied with 32 feet of usable electrical supply
cable outside the station to connect to the alarm panel. The cable
shall be installed in the basin by the manufacturer. The quick disconnect
shall require no tools for connecting, seal against water before the
electrical connection is made, and include radial seals to assure
a watertight seal regardless of tightening torque. The accessway shall
also include an integral two-inch vent to prevent sewage gases from
accumulating in the tank.
The pump discharge shall be equipped with a factory-installed, gravity-operated
flapper-type integral check valve built into the stainless steel discharge
piping. The check valve will provide a full-ported passageway when
open, and shall introduce a friction loss of less than six inches
of water at maximum rated flow. Moving parts will be made of a 300
series of stainless steel and fabric reinforced synthetic elastomer
to ensure corrosion resistance, dimensional stability and fatigue
strength. A nonmetallic hinge shall be an integral part of the flapper
assembly providing a maximum degree of freedom to assure seating even
at a very low back-pressure. The valve body shall be an injection
molded part made of an engineered thermoplastic resin. The valve shall
be rated for continuous operating pressure of 235 psi.
The pump discharge shall be equipped with a factory-installed, gravity-operated
flapper-type integral anti-siphon valve built into the stainless steel
discharge piping. Moving parts will be made of 300 series stainless
steel and fabric reinforced synthetic elastomer to ensure corrosion
resistance, dimensional stability and fatigue strength. A nonmetallic
hinge shall be an integral part of the flapper assembly, providing
a maximum degree of freedom to ensure proper operation even at a very
low pressure. The valve body shall be injection-molded from an engineered
thermoplastic resin. The anti-siphon port diameter shall be no less
than 60% of the inside diameter of the pump discharge piping.
The grinder pump station shall have a cartridge type, easily removable
core assembly consisting of pump, motor, grinder, all motor controls,
check valve, anti-siphon valve, level controls, electrical quick disconnect
and wiring. The core unit shall be installed in the basin by the manufacturer.
The core unit shall seal to the tank deck with a stainless steel latch
assemble. The latch assembly must be actuated utilizing a single quick-release
mechanism requiring no more than a half turn of a wrench. The watertight
integrity of each core unit shall be established by a one-hundred-percent
factory test at a minimum of 5 PSIG.
All necessary motor starting controls shall be located in the cast-iron
enclosure of the core unit secured by stainless steel fasteners. The
wastewater level sensing controls shall be housed in a separate enclosure
from the motor starting controls. The level sensor housing must be
sealed via a radial-type seal. The level sensing control housing must
be integrally attached to a pump assembly so that it may be removed
from the station with the pump and in such a way as to minimize the
potential for the accumulation of grease and debris accumulation,
etc. The level sensing housing must be high-impact thermoplastic copolymer
over-molded with a thermoplastic elastomer.
Nonfouling wastewater level controls for controlling pump operation
shall be accomplished by monitoring the pressure changes in an integral
air column connected to a pressure switch. The air column shall be
internally molded from a thermoplastic elastomer suitable for use
in wastewater and with excellent impact resistance. The air column
shall have only a single connection between the water level being
monitored and the pressure switch. All connections are to be sealed
radially with redundant O-rings. The level detection device shall
have no moving parts in direct contact with the wastewater and shall
be integral to the pump core assembly in a single, readily exchanged
unit. Depressing the push-to-run button must operate the pump even
with the level sensor housing removed from the pump.
All fasteners throughout the assembly shall be 300 series stainless
steel. High-level sensing will be accomplished in the manner detailed
above by a separate air column sensor and pressure switch of the same
type. Closure of the high-level sensing device will energize an alarm
circuit as well as a redundant pump-on circuit. For increased reliability,
pump ON/OFF and high-level alarm functions shall not be controlled
by the same switch. To assure reliable operation of the pressure switches,
each core shall be equipped with a factory installed equalizer diaphragm
that compensates for any atmospheric pressure or temperature changes.
The grinder pump will be furnished with a 6 conductor 14 gauge, type
SJOW cable, pre-wired and watertight to meet UL requirements with
a factory-installed NEMA 6P disconnect half attached to it.
Each grinder pump station shall include a NEMA 4X, UL-listed alarm
panel suitable for wall or pole mounting. The NEMA 4X enclosure shall
be manufactured of thermoplastic polyester to ensure corrosion resistance.
The enclosure shall include a hinged, lockable cover with padlock,
preventing access to the electrical components and creating a secured
safety front to allow access only to authorize personnel. The enclosure
shall not exceed 10.5 inches by 14 inches by seven inches.
The alarm panel shall contain one fifteen-amp, double-pole circuit
breaker for the pump core's power circuit and one fifteen-amp
single-pole circuit breaker for the alarm circuit. The panel shall
contain a push-to-run feature, an internal run indicator and a complete
alarm circuit. All circuit boards in the alarm panel are to be protected
with a conformal coating on both sides, and the AC power circuit shall
include an auto resetting fuse.
The alarm panel shall include the following features: external
audible and visual alarm; push-to-run switch; push-to-silence switch;
redundant pump start; and high-level alarm capacity. The visual alarm
lamp shall be inside a red, oblong lens at least 3.75 inches in length
by 2.38 inches in width by 1.5 inches in height. The visual alarm
shall be mounted to the top of the enclosure in such a manner as to
maintain NEMA 4X rating. The audible alarm shall be externally mounted
on the bottom of the enclosure, capable of 93dB at two feet. The audible
alarm shall be capable of being deactivated by depressing a push-type
switch that is encapsulated in a weatherproof silicone boot and mounted
on the bottom of the enclosure (push-to-silence button).
All grease interceptors shall be properly sized in accordance with
the Table 10-3 of the 2009 Uniform Plumbing Code and shall be based
on the number of DFUs. The minimum size of interceptor shall be 1,000
gallons of effective volume, and the minimum depth of liquid shall
be 46 inches.
The interceptor shall be designed to remove grease from effluent
by gravity and be made of concrete construction, shall be coated both
on the inside and on the outside, and shall be tested in the same
manner as the requirements for manholes and other concrete structures.
The inlet and outlet pipe shall have a two-way cleanout tee installed.
Inlet piping shall enter at four inches above the liquid level. Inlet
piping shall connect to a tee, which shall extend to 12 inches below
the water level. The outlet pipe shall start at a depth as shown on
the standard details above the bottom of the interceptor and extend
vertically to a tee. The tee and pipe shall be not less than four
inches in diameter. The tee shall be installed with the run in the
vertical direction.