Penstocks

Introduction

The Fernco HDPE Penstock is constructed using HDPE and Grade 316 stainless steel.

The Penstock has a vertically moving door manufactured in HDPE with stainless steel supports. The door incorporates an EPDM rubber lip seal to provide a seal against the wall plate. The gate operates within a stainless steel frame with HDPE guides.

A rubber sealing tape is secured between the frame and the mounting wall, which is compressed during installation to provide a seal.

Handling

The HDPE Penstock should only be transported when laid flat with the door plate facing upwards. It can then be lifted by means of suitable equipment.

Where chains or slings are used for handling purposes, the frame should be protected using cloth sacking or similar material.

Fully trained personnel should carry out all necessary lifting.

Storage

It is recommended to store the penstock laid down flat with the door plate facing upwards, free of dust, dirt and moisture.

Mounting Set

• Rubber sealing tape (5mm thick)
• Chemical anchor capsules
• Fixtures and accessories

Tools Required

• Appropriate PPE
• Utility knife
• Marker pen
• Suitable drill
• 12mm drill bit
• Torque wrench
• 17mm socket
• 4mm Allen key + 10mm spanner for BCSAP
• Hammer

Recommended Maximum Temperature

• Constant 80°C
• Intermittent 100°C

Penstock Installation Sequence

Before commencing installation, check the mounting wall is clean and flat. Any deformities in the wall will impede the performance of the sealing tape.

1. Marking the Mounting Face

1. With suitable lifting equipment, lift the penstock and adjust it to ensure it is vertical and level.
2. Check and adjust the penstock into the correct position, ensuring the invert of the pipe is flush with the invert of the penstock opening.
3. Mark all of the mounting holes.
4. Penstocks DN300 and over have additional mounting holes above the penstock opening. These are accessed by fully closing the penstock. Specific countersunk drop-in anchors are supplied in the mounting kits for these sizes. They are installed using an anchor setting tool (T-M10PUNCH), available separately.
5. Remove the penstock.

Standard Chemical Anchor Set

• 316 Stainless Steel M10 threaded stud
• Chemical anchor capsules
• 316 Stainless Steel nuts and washers

Table 1 – Mounting Set Installation Data

Table 2 – Curing Time Data

2. Procedure for Installing Chemical Anchor Attachments

1. Using a 12mm drill bit, drill the mounting holes to a depth of 90mm in their required positions.
2. DN300 and above – Drop-in anchor installation: For the mounting holes above the door, drill to a depth of 40mm.
3. Clean out the drilled holes, removing any dust or debris. Suitable eye protection must be worn.
4. Insert a chemical anchor capsule into each hole.
5. DN300 and above – Drop-in anchor installation: Place the anchor inside the hole and drive the anchor setting tool (or equivalent) into the anchor with a hammer until flush with the anchor base.
6. Attach the M10 stud to a suitable drill.
7. Place the end of the stud into the hole, then operate the drill at high speed and push the stud through the chemical anchor to the back of the hole. Once the back of the hole is reached, stop the drill to prevent resin escaping.
8. Carefully remove the drill from the stud. Take care not to move the stud.
9. During the curing time, proceed to placing the rubber sealing tape.

3. Placing the Rubber Sealing Tape

1. Ensure that the penstock wall plate is clean and smooth.
2. The sealing tape has adhesive on one side with a protective layer. Cut the tape approximately 20mm longer than required, remove the protective layer and fit it onto the frame.
3. Cut the tape to length and square the corners so they connect properly.
4. Drill holes through the tape using the mounting holes in the penstock as a guide.
5. If installing two layers of rubber sealing tape, ensure the second layer overlaps any joints in the first layer.

4. Final Installation Steps

1. Place the penstock over the studs, then place a washer and nut onto each stud and tighten by hand. If applicable, screw the corresponding threaded bolts into the anchors by hand.
2. Once all nuts and washers have been placed, tighten the nuts evenly to the recommended torque. If applicable, also tighten the threaded bolts into the anchors. Countersunk bolts should be flush so that the seal does not get damaged during operation.
3. All fixtures should be tightened in the recommended number pattern to 8Nm using a torque wrench. The sealing tape must be compressed evenly to ensure a good seal.
4. For penstocks DN300 and above, additional anchor mounting holes must also be tightened within the number pattern, ensuring opposite mounting holes are selected sequentially.

Installation of an Extension Spindle

1. Remove the BS Cap using a 4mm Allen key and a 10mm spanner.
2. Place the extension spindle over the spindle of the penstock.
3. Place the upper bracket 150mm below the cover level or the top of the spindle extension. Divide the remaining brackets evenly over the length of the extension spindle (one additional bracket for every 3m).
4. Using the guide bracket as a template, mark on the wall where to drill for the mounting points.
5. Remove the extension spindle.
6. Install the brackets as required.
7. Reinstall the extension spindle through the guide brackets and secure to the penstock using the bolts provided. Adjust bracket positions if necessary to ensure correct alignment.
8. Fit the BSCAP in the top of the extension spindle and secure using the bolts provided. The handwheel and T-Key will also fit onto this.

Post-Installation Checks

To ensure effective operation, the following checks are recommended before leaving site:

• Check the frame is square and has not deformed.
• Clean away any debris from the penstock and ensure the invert of the orifice is clear.
• Double check all fixings are secured to the required torque.
• Check alignment of the extension spindle.

Note: Do not use excessive force when opening or closing a penstock door, as damage could occur.

When correctly installed, the penstock will provide a 60+ year life expectancy.

Maintenance Recommendations for HDPE Penstocks

1. Clean the unit by hosing it down to remove grit or debris. This should be done with the gate in both the open and closed positions.
2. Check that nuts and bolts are tightened to the correct torque.
3. Inspect the frame, door and seals for damage.
4. Check operating equipment for damage and freedom of movement, ensuring there are no worn parts.
5. Check for leakage between the frame and the mounting wall. If leakage persists, remove the penstock, replace the sealing tape and reinstall.

Frequency of Inspection

The inspection frequency should be based on site conditions. In aggressive environments or locations with large amounts of silt or debris, more frequent inspections are strongly recommended.

Materials & Construction

• Backplate, side guides, and gate: HMWPE (HDPE grade PE500) for increased impact strength and durability versus industry standard PE300.
• Frame and support structure: 1.4401 Stainless Steel (316 marine grade) as standard for all internal and external steel components giving superior corrosion resistance.
• Seals: Resilient, self-adjusting EPDM seal designed for consistent compressive isolation. Nitrile or Viton seals can be supplied on request for installations with hydrocarbon or petrochemical contaminants.
• Threaded Nut: A Polyacetal (POM) nut is used as it is a “friction” material which is resistant to wear and exhibits self-lubricating properties, increasing the service life of the valve.

Drive & Operation

• Direction of closure: Anti-clockwise to close.
• Spindle: Non-rising TR25x5 spindle as standard; non-rising spindle options are available. Link to PS
• Spindle Cap: Supplied fitted with a BS Cap as standard for operation with a T-Key or extension spindle and hand wheel, all operational information can be found here in the Operation Guide.

Performance & Compliance

• Standards: All Fernco Penstocks are manufactured to, and exceed the performance requirements of, Class 5 of DIN16569-4 and BS7775 up to 7mWC. Fernco penstocks hold a WRc approval with the assessment schedule and testing performance found in the downloads tab.
• Head loss: Full suite of head loss data is available on request.
• UV stability & corrosion resistance: Suitable for prolonged outdoor exposure and aggressive media
• Security: HDPE has almost no weigh-in value, making theft undesirable.

Environmental

• Design Life: Fernco Penstocks are adequate for a 60 year design life.
• Microplastics: HMWPE material contains at least 3% carbon black which is the most effective stabiliser for polyethylene in regard to UV degradation and increasing suitability for prolonged exposure. The carbon black absorbs light to prevent the radiation from breaking down the polymer chains and polluting the waterways with PE microplastic.

Introduction

The Fernco HDPE Penstock is constructed using HDPE and Grade 316 stainless steel.

The Penstock has a vertically moving door manufactured in HDPE with stainless steel supports. The door incorporates an EPDM rubber lip seal to provide a seal against the wall plate. The gate operates within a stainless steel frame with HDPE guides.

A rubber sealing tape is secured between the frame and the mounting wall, which is compressed during installation to provide a seal.

Handling

The HDPE Penstock should only be transported when laid flat with the door plate facing upwards. It can then be lifted by means of suitable equipment.

Where chains or slings are used for handling purposes, the frame should be protected using cloth sacking or similar material.

Fully trained personnel should carry out all necessary lifting.

Storage

It is recommended to store the penstock laid down flat with the door plate facing upwards, free of dust, dirt and moisture.

Mounting Set

• Rubber sealing tape (5mm thick)
• Chemical anchor capsules
• Fixtures and accessories

Tools Required

• Appropriate PPE
• Utility knife
• Marker pen
• Suitable drill
• 12mm drill bit
• Torque wrench
• 17mm socket
• 4mm Allen key + 10mm spanner for BCSAP
• Hammer

Recommended Maximum Temperature

• Constant 80°C
• Intermittent 100°C

Penstock Installation Sequence

Before commencing installation, check the mounting wall is clean and flat. Any deformities in the wall will impede the performance of the sealing tape.

1. Marking the Mounting Face

1. With suitable lifting equipment, lift the penstock and adjust it to ensure it is vertical and level.
2. Check and adjust the penstock into the correct position, ensuring the invert of the pipe is flush with the invert of the penstock opening.
3. Mark all of the mounting holes.
4. Penstocks DN300 and over have additional mounting holes above the penstock opening. These are accessed by fully closing the penstock. Specific countersunk drop-in anchors are supplied in the mounting kits for these sizes. They are installed using an anchor setting tool (T-M10PUNCH), available separately.
5. Remove the penstock.

Standard Chemical Anchor Set

• 316 Stainless Steel M10 threaded stud
• Chemical anchor capsules
• 316 Stainless Steel nuts and washers

Table 1 – Mounting Set Installation Data

Table 2 – Curing Time Data

2. Procedure for Installing Chemical Anchor Attachments

1. Using a 12mm drill bit, drill the mounting holes to a depth of 90mm in their required positions.
2. DN300 and above – Drop-in anchor installation: For the mounting holes above the door, drill to a depth of 40mm.
3. Clean out the drilled holes, removing any dust or debris. Suitable eye protection must be worn.
4. Insert a chemical anchor capsule into each hole.
5. DN300 and above – Drop-in anchor installation: Place the anchor inside the hole and drive the anchor setting tool (or equivalent) into the anchor with a hammer until flush with the anchor base.
6. Attach the M10 stud to a suitable drill.
7. Place the end of the stud into the hole, then operate the drill at high speed and push the stud through the chemical anchor to the back of the hole. Once the back of the hole is reached, stop the drill to prevent resin escaping.
8. Carefully remove the drill from the stud. Take care not to move the stud.
9. During the curing time, proceed to placing the rubber sealing tape.

3. Placing the Rubber Sealing Tape

1. Ensure that the penstock wall plate is clean and smooth.
2. The sealing tape has adhesive on one side with a protective layer. Cut the tape approximately 20mm longer than required, remove the protective layer and fit it onto the frame.
3. Cut the tape to length and square the corners so they connect properly.
4. Drill holes through the tape using the mounting holes in the penstock as a guide.
5. If installing two layers of rubber sealing tape, ensure the second layer overlaps any joints in the first layer.

4. Final Installation Steps

1. Place the penstock over the studs, then place a washer and nut onto each stud and tighten by hand. If applicable, screw the corresponding threaded bolts into the anchors by hand.
2. Once all nuts and washers have been placed, tighten the nuts evenly to the recommended torque. If applicable, also tighten the threaded bolts into the anchors. Countersunk bolts should be flush so that the seal does not get damaged during operation.
3. All fixtures should be tightened in the recommended number pattern to 8Nm using a torque wrench. The sealing tape must be compressed evenly to ensure a good seal.
4. For penstocks DN300 and above, additional anchor mounting holes must also be tightened within the number pattern, ensuring opposite mounting holes are selected sequentially.

Installation of an Extension Spindle

1. Remove the BS Cap using a 4mm Allen key and a 10mm spanner.
2. Place the extension spindle over the spindle of the penstock.
3. Place the upper bracket 150mm below the cover level or the top of the spindle extension. Divide the remaining brackets evenly over the length of the extension spindle (one additional bracket for every 3m).
4. Using the guide bracket as a template, mark on the wall where to drill for the mounting points.
5. Remove the extension spindle.
6. Install the brackets as required.
7. Reinstall the extension spindle through the guide brackets and secure to the penstock using the bolts provided. Adjust bracket positions if necessary to ensure correct alignment.
8. Fit the BSCAP in the top of the extension spindle and secure using the bolts provided. The handwheel and T-Key will also fit onto this.

Post-Installation Checks

To ensure effective operation, the following checks are recommended before leaving site:

• Check the frame is square and has not deformed.
• Clean away any debris from the penstock and ensure the invert of the orifice is clear.
• Double check all fixings are secured to the required torque.
• Check alignment of the extension spindle.

Note: Do not use excessive force when opening or closing a penstock door, as damage could occur.

When correctly installed, the penstock will provide a 60+ year life expectancy.

Maintenance Recommendations for HDPE Penstocks

1. Clean the unit by hosing it down to remove grit or debris. This should be done with the gate in both the open and closed positions.
2. Check that nuts and bolts are tightened to the correct torque.
3. Inspect the frame, door and seals for damage.
4. Check operating equipment for damage and freedom of movement, ensuring there are no worn parts.
5. Check for leakage between the frame and the mounting wall. If leakage persists, remove the penstock, replace the sealing tape and reinstall.

Frequency of Inspection

The inspection frequency should be based on site conditions. In aggressive environments or locations with large amounts of silt or debris, more frequent inspections are strongly recommended.

Materials & Construction

• Backplate, side guides, and gate: HMWPE (HDPE grade PE500) for increased impact strength and durability versus industry standard PE300.
• Frame and support structure: 1.4401 Stainless Steel (316 marine grade) as standard for all internal and external steel components giving superior corrosion resistance.
• Seals: Resilient, self-adjusting EPDM seal designed for consistent compressive isolation. Nitrile or Viton seals can be supplied on request for installations with hydrocarbon or petrochemical contaminants.
• Threaded Nut: A Polyacetal (POM) nut is used as it is a “friction” material which is resistant to wear and exhibits self-lubricating properties, increasing the service life of the valves.

Drive & Operation

• Direction of closure: Clockwise to close.
• Spindle: Non-rising TR20x4 spindle as standard; rising spindle options are available. Link to PSRS
• Spindle Cap: Supplied fitted with a BS square cap as standard for operation with a T-Key or extension spindles, all operational information can be found here in the Operation Guide.

Performance & Compliance

• Standards: All Fernco Penstocks are manufactured to, and exceed the performance requirements of, Class 5 of DIN16569-4 and BS7775 up to 4mWC. Fernco penstocks hold a WRc approval with the assessment schedule and testing performance found in the downloads tab.
• Head loss: Full suite of head loss data is available on request.
• UV stability & corrosion resistance: Suitable for prolonged outdoor exposure and aggressive media
• Security: HDPE has almost no weigh-in value, making theft undesirable.

Environmental

• Design Life: Fernco Penstocks are adequate for a 60 year design life.
• Microplastics: HMWPE material contains at least 3% carbon black which is the most effective stabiliser for polyethylene in regard to UV degradation and increasing suitability for prolonged exposure. The carbon black absorbs light to prevent the radiation from breaking down the polymer chains and polluting the waterways with PE microplastic.

Materials & Construction

• Backplate, side guides, and gate: For HDPE valves HMWPE (HDPE grade PE500) is used for increased impact strength and durability versus industry standard PE300. For fully strainless valves a welded stainless steel construction with integral u-shaped frame is used with 1.4404 or 1.4301 (316L or 304) Stainless Steel available.
• Frame and support structure: 1.4401 Stainless Steel (316 marine grade) as standard for all internal and external steel components giving superior corrosion resistance.
• Seals: Resilient, self-adjusting EPDM seal designed for consistent compressive isolation. Nitrile or Viton seals can be supplied on request for installations with hydrocarbon or petrochemical contaminants.
• Threaded Nut: For HDPE valves a Polyacetal (POM) nut is used as it is a “friction” material which is resistant to wear and exhibits self-lubricating properties, increasing the service life of the valves. A brass nut is used to compensate for the additional weight of the fully stainless steel valves.

Drive & Operation

• Direction of closure: Clockwise to close.
• Spindle: The size of the spindle will change to suit the size of the valve; rising spindle options are available.
• Actuation: Fernco’s range of HDPE non-rising spindle penstocks can be supplied with coded kit sets that allow for the installation and operation of the valve using a multi-turn actuator or gearbox. Fernco’s range of stainless steel penstocks can be supplied with all parts to allow for the installation and operation of the valve using a multi-turn actuator or gearbox. Link to operational guide

Performance & Compliance

• Standards: All Fernco Penstocks are manufactured to, and exceed the performance requirements of, Class 5 of DIN16569-4 and BS7775.
• Head loss: Full suite of head loss data is available on request.
• UV stability & corrosion resistance: Suitable for prolonged outdoor exposure and aggressive media
• Security: HDPE has almost no weigh-in value, making theft undesirable.

Environmental

• Design Life: Fernco Penstocks are adequate for a 60 year design life.
• Microplastics: HMWPE material contains at least 3% carbon black which is the most effective stabiliser for polyethylene in regard to UV degradation and increasing suitability for prolonged exposure. The carbon black absorbs light to prevent the radiation from breaking down the polymer chains and polluting the waterways with PE microplastic.

Actuators and gearboxes are sized by the required input torque, if the penstock is installed in an application where 7mWC head pressure isn’t required then the actuator could be sized down to suit. For penstocks installed where the input torque exceeds 80Nm, a gearbox is advised to reduce this to a safe, operable level. A position indicator can be supplied with a gearbox or handwheel to clearly display the penstock door position.

Fernco use ISO 5210:2023 for all actuator accessories and the standard B3 keyway with a 20mm input shaft.

Torque Matrix

* PS100 not suitable for PSACT-DM
** Gearbox recommended

Drive Mount Options