COPOLYMER FLAP GATES

Plasti-Fab flap gates act as a check valve by allowing flow to pass in one direction only. Any seating head will be held back, and unseating heads will pass. Like all Plasti-Fab products, Copolymer flap gates are corrosion resistant and long lasting. Key features include: Very low leakage rates, Rugged construction, Light weight when compared to cast iron or steel gates, Lower discharge head requirements, and Virtually no maintenance.

Plasti-Fab manufactures three distinct styles of flap gate.

Type I flap gates have a rigid door with a flexible neoprene hinge/seal arrangement. This is generally a Copolymer gate with a circular or rectangular body. Type I flap gates range in size from 4 inches to 36 inches.

Type II flap gates also have a rigid door, but use a stainless steel hinge mechanism to support the door. These gates will generally be used to close off larger openings and can be circular or rectangular. Double hinges are often required to help center and support the gate.

Type III flap gate has a flexible cover or door, and is generally a larger tide or back flow control gate. This style of gate will most often be fabricated of stainless steel, will be square or rectangular, and can have a single or multiple covers. Type Ill gates are wall mounted and are available up to 8 feet square.

GATE BODY: The Copolymer flap gate has a reinforced composite (FRP) body. Standard molds exist for all common pipe sizes from 4” through 60” diameter. Rectangular Copolymer gates range in size from 24” to 60”. Stainless steel gate bodies will be of T-304 or T-316 stainless steel as required by the application. These gates are typically square or rectangular and are available from 24” to 120”.

Depending on the style, size and application, flap gates will be bolted directly to a wall or bulkhead, flange mounted to a pipe, or clamped to the exposed end of a pipe.

COVER OR FLAP: The Type I hinge/seal assembly is a one piece cover that mounts directly to the gate body and will never need adjustment. It is perfectly aligned with the seating surface of the gate to produce a tight seal every time. Covers from 4” to 21” diameter are molded neoprene with an internal steel reinforcing disc. Larger diameter and rectangular covers are of molded neoprene and will have an FRP cover to provide the necessary structural support. Reinforcing belts or plys are vulcanized into the flap to prevent sagging.

The Type II gate cover uses a single or double stainless steel hinge, and is preferred by some engineers because of its more traditional look. The stainless steel hinge bolts directly to an FRP cover with a neoprene facing seal. Half inch diameter hinge pins with nylon sleeves permit the cover to rotate and seal tightly against the gate seat.

Type Ill flexible covers clamp directly to the gate body and frequently require additional support to maintain a flat seat. Generally steel reinforcing bars are molded into the neoprene flap, or external horizontal stiffeners are affixed to the cover. Sometimes vertical stainless steel support angles can be built into the clear opening of the gate body to provide the needed support.

LOCATION: Flap gates are most commonly found at the end of a pipe line for back flow control, or to seal out pests and provide vector control. They are seen at many river out falls, in tidal and marshy areas, and around lakes or reservoirs with fluctuating water levels. Water and wastewater treatment plants are beginning to use more of these gates.

Copolymer & Stainless Steel Flap Gates

                        Type I                                     Type II                                    Type Ill

Gate Cover      Rigid                                       Rigid                                       Flexible

Hinge              Flexible hinge/seal                   Stainless Steel                         Flexible

Gate Body
Typical            4” to 36”                                 24” to 72”                              36” to 96”
size range                                                       

Material           Copolymer                              Copolymer & S/S                    Stainless Steel

Shape              Round                                     Round or                                 Rectangular
                                                                        Rectangular

Mounting        Wall, Flange or                        Wall or Flange                         Wall mounted
Compression Ring

WHY BUY PLASTI-FAB?

1. High corrosion resistance. Great for sea water and coastal areas or other harsh environments, especially when used with the neoprene seal/hinge.
2. Excellent leakage performance.
3. Light weight fiberglass.
4. Low head loss.
5. Little or no maintenance.

SLIDE GATE

A Plasti-Fab slide gate is a sophisticated stop gate that employs a stem or shaft coupled to a mechanical lifting device to raise and lower the gate. The lift and stem make it possible to raise heavy loads easily, and provide a positive force to seat the gate against the bottom seal. This combination makes it easier to operate gates that are some distance below the operating surface, or that will be cycled more frequently. Slide gates are commonly used in open channel applications, to close off a wall opening, or to cover a pipe that is flush with the wall. Slide gates may or may not include seals depending on this application. The slide gate may be constructed as a sandwich-style gate, a one-inch solid FRP gate, or as a Heavy Duty Titeseal gate.

LIFTS Slide gates may be operated manually, electrically, pneumatically, or hydraulically. The lifts may be mounted on the head rails of a self-contained gate, or on a pedestal or bench stand if the gate is not self-contained. A floor box and square nut make it possible to keep the entire gate is not self-contained. A floor box and square nut make it possible to keep the entire gate and operator out of sight or below the floor level. Pneumatic or hydraulic operators may be used in explosive atmospheres or on gates that need to be closed quickly. Electric operators generally operate at 12 inches per minutes and have many options. If the width of the gate is twice that of the height, a tandem lift will be required.

STEMS Stems will normally be T-304 or T-316 stainless steel as required by the application or specification.

GUIDES Guides may be embedded, surface mounted, or in-channel mounted. Surface mounted guides bolt to the face of the wall around an opening. In-channel guides bolt to the side surface of an existing channel. Embedded guides are either attached to form work and encased with the wall pour, or they may be grouted into a pre-formed blockout at a later time. Most Plasti-Fab guides are fiberglass pultruded shapes that have been designed to make installation easier and provide a longer service life. In special situations, Plasti-Fab may choose to use stainless steel.                            

All self-contained gates are factory adjusted and the limit nuts are set on the stem so that no further adjustment is necessary in the field.

SEALS Not all slide gates need seals to meet their performance requirements. When seals are used, the design will vary according to the leakage requirement. All seals are virgin molded neoprene. J-seals will be affixed to the gate or guide depending upon the type of guide used and the type of service expected. Flush bottoms seals will normally be used to provide a resilient bottom seating surface and to prevent debris from collecting in the groove.

MATERIALS OF CONSTRUCTION Ninety percent of the time, the gate and guide will be fiberglass and the gate hardware will be stainless steel. Most are sandwich construction with or without internal steel reinforcing. Plasti-Fab also builds a rugged one inch solid FRP gate that is not available from any other source.

LOCATION Slide gates are found throughout wastewater plants, industrial treatment facilities and storm water control systems. Look for them in plant headworks, diversion boxes, by-pass and feeder channels, ponds and aerated lagoons and in chlorination basins. Plasti-Fab has also built FRP diversion manholes that contain integral slide gates for existing buried lines.

WHY BUY PLASTI-FAB?

Plasti-Fab gates offer high corrosion resistance to a very wide range of acids, caustics, salt water and other aggressive chemicals.

Plasti-Fab offers a very broad range of gates including sandwich style, one-inch thick solid FRP gates, stainless steel and aluminum if required.

Plasti-Fab has over 25 years experience in fiberglass gate design and installation, and several thousand slide gates of every conceivable type currently in use in the United States and Canada.

Plasti-Fab has worked with every major lift manufacturer and will supply whatever type is required to meet the project specification. You can request handwheel, geared mechanical lifts, portable operators, electric actuators, pneumatic or hydraulic actuators.  

Fiberglass slide gates are lightweight and easy to install.

WEDGING TITESEAL® SLIDE GATE Patent #4.524.950

The Wedging Titeseal® Slide Gate was developed and patented by John Vitas at Plasti-Fab. It is the tightest sealing slide gate available on the market today. The Wedging Titeseal® design is capable of reaching extremely low leakage rates. In our literature we say less than 100 cc/mm/foot of wetted perimeter. This is 4 to 5 times lower leakage than permitted by AWWA C-501, and applies to both seating and unseating heads. In actual practice, the Wedging Titeseal® Gates have been adjusted to the point of being nearly drip-tight.

NOTE: There is no top seal on a Wedging Titeseal® Gate so water can flow over the top. The Wedging Titeseal® Gate MUST be taller than the maximum water level in order to be effective.

When requested, Plasti-Fab will run factory leakage tests on any Titeseal® gate, and provide a written report of the results to the engineer or client. Testing must be set up ahead of time, preferably in the specification.

The Wedging Titeseal® Gate is used in many of the same areas and applications as a conventional slide gate. It is frequently used by industries for spill control, emergency shutoff and in aggressive flow streams. Here, the client is willing to pay a premium for the added security and reliability.

An important feature of the Wedging Titeseal® Gate is the location of the J-seals on the face of the gate where they may be adjusted or removed if necessary without dewatering the channel.

The Wedging Titeseal® Gate can be fabricated using 1” thick solid FRP, Sandwich construction, Heavy Duty Copolymer, Stainless Steel, or Aluminum.

LIFTS The Wedging Titeseal® design relies on an operator to achieve a complete mechanical seal. The lift can be operated manually, electrically, pneumatically or hydraulically. The lifts are mounted on the head rail of self-contained gates. A pedestal, bench stand or floor box can be used on gates that are below the operating surface. Pneumatic or hydraulic operators may be used where power isn’t readily available, or the gate needs to be closed quickly, or safety restrictions limit the use of electricity.

GUIDES The Wedging Titeseal® Gate use Plasti-Fab standard FRP pultruded guides that can be embedded, surface mounted or in-channel mounted. The wedging assembly is an integral part of the guide. Surface mounted guides bolt to the face of the wall around an opening. In-channel guides bolt to the inside face of an existing channel. Embedded guides can be nailed to the concrete forms and encased with the wall pour, or they may be grouted into a blockout at a later time.

SEALS A neoprene flush bottom seal fills the bottom groove of the guide, and neoprene J-seals are mounted down each side and across the bottom of the gate. The J-seals are aligned with the fiberglass wedging bar and factory adjusted so that the gate sealing capability increases as the gate is driven down to the closed position. This often results in nearly water-tight performance. This patented seal design is unique in the market today.

LOCATIONS Wedging Titeseal® Gates should be considered in any area where high performance gates are required. This gate is used often for industrial spill containment or emergency shut-off at airports, military and other Federal sites where performance is critical.

WHY BUY PLASTI-FAB?

1. The patented seal design is unequaled in leakage performance. Published leakage rates of 100 cc/minute/foot of wetted gate perimeter.
2. The unique seal design allows for seal adjustment or removal without dewatering a channel.
3. For unusual or especially tough applications Plasti-Fab has experience with a large variety corrosion resistant high performance metals and resins.
4. The Wedging Titeseal® Gate will perform when needed for emergency shut-off, spill containment or any other critical shut off situation.
5. Plasti-Fab’s experience with customer requirements will help you get the job done right the first time.
6. Fiberglass gates are lightweight and easy to install.
7. After the gate is raised slightly, the seal is no longer in contact with its seat. This eliminates seal wear and makes the gate easy to operate.

HEAVY DUTY TITESEAL SLUICE GATE

The Heavy duty Titeseal Copolymer Sluice Gate is a non-metallic, corrosion resistant sluice gate that provides the engineer with a superior alternative to other plastic gates and competes well with stainless steel and cast iron gates. It is designed to handle high head applications of 25 feet or more in seating and unseating service. The guide includes a top closure bar that allows the gate to seal around all four sides. This gate is also often used for open channel weir applications. This gate is like the Wedging Titeseal gate, a high performance, low leakage slide gate.

The gates are individually fabricated and can be designed to cover most opening. Sizing can range from about one foot square to over ten feet in width and height.

Copolymer gates can range in thickness from 2-l/2 inches to over 12 inches depending on the head and deflection requirement.

The gate is fabricated using a reinforced copolymer composite material (FRP), which totally encapsulates an internal structural steel matrix, and has no seams, joints or cut edges. The core of the gate is completely sealed against any corrosive attack by water or chemicals that might be present in the stream.

Heavy Duty Titeseal sluice gates do not use wall thimbles. Instead, the guide is anchored to a flat surface and approximately one inch of grout is used to permanently seal between the guide and the wall. The guide is normally fabricated using T-304 or T-316 stainless steel, but FRP guides and other more exotic metals are available. Plasti-Fab has fabrication experience with Monel, Hasalloy and Aquamet to name a few.

GuidesThe gates require specially formed guides, but these will still be classified as embedded, surface mounted, or in-channel according to how they are mounted. Surface mounted guides bolt to the face of the wall around an opening using special slotted clips that slide onto the anchor bolts. In-channel guides bolt to the inside face of an existing channel.

SEALS Heavy Duty Titeseal Sluice Gates have a virgin neoprene J-seal and wedged bottom seal mechanically fastened to the gate. Neoprene forms a true seal that has high resilience and durability, and will not bridge or gap over small debris. It has been used successfully by the U. S. Army Corps of Engineers in hydro-electric dams for the past seventy years as the proven seal of choice. Plasti-Fab will not use sponge rubber, which has low compression set characteristics and low tear strength.

Mounted on the opposite side of the gate is a UHMW low-friction sliding surface which helps to reduce the lifting force required to move the gate. As the gate starts to open, the seal is released from contact with the wedge. This allows the gate to move freely in the guide with lower operating forces. The adjustable wedging bar in the guide allows the gate to be fine-tuned to achieve the lowest possible leakage rates. The end result is leakage rates that are much less than the AWWA standard for sluice gates (AWWA C-501 establishes leakage of no more than 0.1 GPM/foot of wetted perimeter for a seating head, and 0.2 GPM/foot of wetted perimeter for unseating heads of 20 feet or less.)

Example A four-foot by four-foot gate with 20 feet of seating head will require nearly 18,000 pounds of thrust to begin upward movement. (16 ft.² gate surfaced X 18 ft. Head to the gate center line X 62.4 lbs/ft.³ H₂O = 17,971 lbs. breakaway force.)

The entire load plus the weight of the gate and stem must be moved by the stem and lift nut, and supported by the head frame and lift. For periods of up to 20 years (sic). In addition, AWWA C-501 sluice gate standards require that this initial gate movement should take place with no more than 25 to 40 pound pull on the handwheel or crank. All this means that proper sizing of the lift, stem, and other gate components is critical.

All lifts used by Plasti-Fab will have ball bearings, and many will be geared. Geared lifts can also be operated by an electric or gas powered portable operator to reduce cycling time. Plasti-Fab also uses electric, pneumatic, and hydraulic actuators. We have worked with most of the major gate and operator manufacturers in the U. S. for over twenty years.

LOCATION May include any size open channels and any wall opening that will have a seating or un-seating head greater than the opening itself.

WHY BUY PLASTI-FAB?

1. The Heavy Duty Titeseal Sluice Gate exceeds any other metallic gates. We can give the owner, engineer, and contractor an alternate to this high-priced proprietary spec., that exceed the functional aspects of the specification in all areas.
2. The seals are mounted to the gate which is a unique feature to most other gates on the market today. This allows the adjustment and replacement of the seals without dewatering of the channel.
3. Plasti-Fab can fabricate using a large variety of high corrosion performance metals and resins.
4. Gate will perform when needed for emergency shut off, spill containment or any other critical shut-off situation.
5. Wide range of experience with customer requirements that will help get the job done right the first time.

How to use a scum skimmer for cleaning your pond?

You! Is your pond too filthy? Do you see scum all around? Yes? Are you looking for a professional cleaner to do the job for you? If it’s a yes, then surely you are wasting your time as well as effort.

With fiber glass scum skimmer, cleaning scum over ponds and any small water body isn’t a daunting task anymore. And more importantly, you don’t need to be an expert. Only if you can read and understand the manual instructions, then half of your job is already done!

Given below are few tips regarding cleaning a pond using scum skimmer:

• The first and foremost thing to do in this regard is reserve 1-2 hours specifically for this purpose. You need to give enough time for this work. If you are planning for a weekend clean up, then make sure, you either complete rest other work or else complete them later.
• Read the manual instructions properly. Though the points are sufficient enough to guide you, but still different manufacturing have some specific usage. Go through that properly; else instead of cleaning your pond, you will end up in breaking the device!
• Lift the lid off the skimmer and take out the net in the front. Shake the net so that any debris would go off.
• Clean the skimmer properly before doing the job and also make sure that you clean it after the job. Else it would lead to slow water flow and would put unnecessary stress on the pump.

PALMER-BOWLUS FLUME GENERAL COMMENTS

The Palmer-Bowlus Flume was originally designed for use in manholes. It is still most commonly installed in pipelines and manholes. However, it is also suitable for open channel applications when a proper transition is used in front of the flume. The flume can use a simple power equation or a more accurate polynomial equation. It can be used with any of the meters available on the market today.

ADVANTAGES

1. The Palmer-Bowlus “U” shaped design and relatively short length make it ideal for retrofitting existing piping systems. This design also allows 4” – 12” flumes to fit through an existing manhole opening.
2. Larger Palmer-Bowlus flumes (typically 48” and larger) can sometimes provide a good alternative to the Parshall. They often give better flow resolution, and may cost less to install.
3. The flume design accelerates the flow as it passes through the flume thus making it “self-cleaning”. Its wide throat is great for passing larger solids and debris.
4. The raised throat helps create positive head for the water to pass out and away from the flume.
5. The Palmer-Bowlus can tolerate a high level of submergence: 85 – 90%!

DISADVANTAGES

1. The Palmer-Bowlus flume was originally designed to fit pipes the same size as the flume. It is now a common practice to install a smaller Palmer-Bowlus flume in a larger channel or pipe. This however, may limit the total amount of flow range that can be accurately used if the wider opening significantly affects the downstream tail water. Above the lower flow range limit, you could experience a progressive over-discharge resulting in a 3 – 5% low reading.
2. Although the Palmer-Bowlus has a fairly good flow range, it is typically not a good style of flume for measuring low flows.
3. Flat or low sloped inlet pipes and channels could create solids settling because of low velocities and the raised throat design. This is especially true during low flow periods. However, the solids will normally pass through the flume when flow picks up.

 

APPLICATION NOTES: Also see “General Flume Design Data”

1. The most common calibration errors are:
   1. Not having the correct measurement location. This should be upstream of the entrance ramp, a distance equal to half the diameter of the flume, or 0/2.
   2. Not having the correct zero point. The zero point is level with the raised throat of the flume. At zero flow you have standing water at the measurement point.
2. Do not expect accurate predictable readings for flows under 5 to 10 GPM even in the smallest (4”) Palmer-Bowlus flume.
3. The Palmer-Bowlus flume will experience submerged conditions at about 85% – 90% of the downstream depth compared to the upstream depth. If at all possible do not design or install a new flume system with the anticipation of it operating in a submerged state.
4. One of the most common misunderstandings is the use of the term “Insert” as it relates to a Palmer-Bowlus flume. A Palmer-Bowlus “Insert” is a flume without an approach section, staff gage, end flanges or mounting slips. “Inserts” are made to fit into a pipe that is the same size as the flume, i.e….a true 6” l.D. pipe will require a 6” 0.0. “Insert” flume.

Note:  

1. The gauging point will be in the pipe or channel ahead of the flume.
2. The true pipe l.D. must be confirmed. Plastic and clay pipes frequently have an irregular ID. — 6” pipe may actually be 5 3/4” ID.
3. Palmer-Bowlus Insert flumes were originally intended for temporary installations such as storm water and I & I studies.

A Palmer-Bowlus “Insert” with Approach is a modification that is sometimes used in order to include the staff gage within the flume. This style will often be used in “roughed-in” U-channels.

Note:  

1. The same installation requirements apply, pipe ID. and flume 0.D. must match.
2. Probe cavities or instrument mountings that increase the O.D. of the flume wall are not allowed.
3. Plasti-Fab has standard molds for this type of flume from 4” through 12” diameter. Flume length including the approach of 3D+1”.

A Palmer-Bowlus Cutback or “exit” style flume is another modification of the Insert flume. In this version of the downstream vertical walls of the flume have been removed to match the height of the half pipe. This allows the outlet end of the flume to be inserted into the downstream pipeline.

Note:  

1. Again, the same installation requirements apply.
2. The cutback flume usually does not include an approach section.
3. The upper flow range will be restricted to about 60 or 70% of full pipe.
4. Use the conservative peak flow as the upper limit.

The Palmer-Bowlus with Approach is sometimes referred to as a “Permanent” or standard flume. The normal length with an approach of 4D + 1”. These flumes have side clips for keying into concrete and a structural flange around both ends. The approach section is desirable because it provides a control area in the flume for measurement, a built-in gage, and a place to mount a meter.

Electrical components and considerations

1. The shelter NEMA ratings most often apply to the smaller instrument and chlorinator shelters. This is intentional because the smaller enclosures are designed and built to resemble a walk-in electrical cabinet. NEMA 3R is our standard and refers to a shelter that will not allow water penetration under heavy storm conditions. Also any internal electrical equipment is isolated from outside contact through any wall openings. NEMA 4X indicates that the shelter is water tight, dust tight, and corrosion resistant, and that the shelter will stay dry inside even when sprayed at close range by a fire hose. For all practical purposes this means that the shelter can not have any exterior vents or openings.
2. An Exhaust Fan is typically used in instrument and sampling shelters. This is mounted high on the shelter wall and is either switch or thermostatically controlled.
3. For shelters that house chlorine and other heavy corrosive gases or chemicals Plasti-Fab will install a Purge Fan near the top of one wall and locate the vent on the opposite wall near the floor. A Purge fan draws fresh air from outside the enclosure and pushes the contaminated air that has settled near the floor out through the low vent. This method assures that the fan and its critical electrical wiring is not exposed to premature failure due to excessive contact with the corrosive gases.
4. Plasti-Fab is also experienced with Class I, Division I & II Explosion Proof requirements, and has supplied a number of shelters meeting these codes.
5. Standard electrical packages normally include a NEMA rated service panel, light & switch, heater with thermostat, fan, convenience outlet and wiring. Other components available include: air conditioners, warning lights, alarms, junction boxes, etc.

CAPABILITY

Plasti-Fab has the specialized capability to take standard shelter units and add customized features to satisfy a wide variety of site and application requirements. Wall height from 7 ft. to 12 ft. are available. Roof style can be flat, gabled or sloping and can be fitted with lift-off panels or completely detachable for crane access to pumps and heavy equipment. Windows and lifting eyes are common accessories. Larger shelters up to 20 feet square can be shipped as knock-down units for quick assembly at the job-site.

Fiberglass shelters and covers can be acoustically lined and tested to limit noise of pumps. They can also be insulated to any degree necessary. Shelters can be made with fire retardant resins, fitted with fire suppression systems, detectors, alarms, shelves and explosion-proof electrical features. Plasti-Fab can add any desired accessory and meet any design requirements.

 

Fiberglass shelters are light weight and easy to transport, and can be skid mounted to increase their mobility. Plasti-Fab shelters are currently being used to house: liquid and dry chlorine systems; chemical feed/storage; medical & biohazardous wastes; instrumentation and water sampling equipment; air quality monitoring equipment; communication systems and equipment; telemetry systems; blowers, generators & pump enclosures; on piers, docks & offshore stations.

If corrosion resistance and long service life are important, expect to see a Plasti-Fab fiberglass shelter handling the job.

 

The Importance of using Scum Skimmer and corrosion preventive products

It is important to use composite fiber glass materials that can control the fluid control equipments for the industry and other infrastructures. The expert team of corrosion resistant equipments can provide good solution for water and wastewater systems. All such professionals provide the best solution for all corrosion equipments and accordingly control the fluids. There are special plastic and other fiber glass materials that can be used just to avoid the corrosion and increase the service period.

Such materials are effective against corrosion and functions smoothly in all environmental conditions. So it is important to use corrosion free or resistant materials for various engineering composites. Here are some materials that come along with various benefits:

• Parshall Flume is a specialized engineered material that helps in acting as a corrosion resistant for different engineering designs and available in various shapes.
• FRP Shelter is completely suitable for all conditions and requires no maintenance. The materials are nonconductive and are normally not susceptible to ruts or any types of decay. Such items are available in different shapes and styles.
• Scum Skimmer is easily installed and needs low maintenance cost, easily installed and effective with their designs. The materials that are engineered with such composites do not corrode so easily enhancing the life period of the material.

For increasing the longevity of engineered goods it is important to use corrosion free materials that can help in enhancing the service period. All such materials are suitable for corrosion and tough natural conditions.