VPC Fiberglass partnered with C.C. Lynch & Associates to design and manufacture a custom 48” diameter x 18’-0” FRP LaserFlow® metering manhole for Carpenter Technologies in Tanner, Alabama.
This engineered fiberglass manhole system was developed to serve as a precision-built flow metering manhole, supporting accurate, long-term open channel flow measurement while simplifying installation and reducing ongoing maintenance requirements. It provides accurate flow measurement where flumes struggle with submerged conditions.
The Engineered Solution
This project featured a fully integrated FRP manhole system specifically designed to accommodate the ISCO LaserFlow sensor. As a factory-fabricated flow meter structure, the system included:
- 48” Ø x 18’-0” (invert to grade) fiberglass manhole basin
- 12” integral through-pipe with factory cutout for LaserFlow®
- Equipment mounting board/bracket
- Integral ladder, flange, and floor
- 2” threaded coupling
- FRP dome cover terminating 12” above finished grade
- UV-resistant gel coat finishes
- ½” minimum wall thickness (manhole basin)
By incorporating the sensor mounting provisions and pipe cutout during manufacturing, VPC delivered a factory-integrated flow meter manhole that eliminated the need for field coring or retrofitting — ensuring proper sensor alignment and a streamlined installation process.
Key Benefits of the Integrated LaserFlow® Manhole System
Non-Contact Flow Measurement
The ISCO LaserFlow® uses advanced non-contact flow measurement technology, combining laser level sensing with velocity measurement for accurate open channel flow monitoring. Because the sensor is not submerged in the flow stream:
- No moving parts in contact with fluid
- Reduced fouling and buildup
- Lower maintenance requirements
- Improved long-term reliability
- Consistent, high-accuracy flow data
Durable FRP Metering Structure
VPC’s fiberglass metering manhole provides a corrosion-resistant alternative to traditional concrete structures. The FRP construction offers:
- Long-term structural integrity
- Corrosion-resistant performance
- UV-resistant gel coat finishes
- Lightweight construction for easier handling and installation
- Extended service life with reduced maintenance
This makes it an ideal solution for facilities seeking a durable, long-lasting manhole alternative to concrete.
Improved Installation Efficiency
As a pre-engineered flow meter vault, factory integration of the through-pipe and sensor cutout helped:
- Eliminate field coring or modifications
- Reduce installation labor
- Ensure proper sensor positioning
- Minimize risk of field alignment errors
- Accelerate overall project timelines
Safe & Accessible Design
The integral ladder, flange, and floor system allow safe access when required, while the above-grade FRP dome cover helps protect the structure and provide secure access to the flow monitoring equipment.
Looking for the Right Fiberglass Metering Manhole System?
If you’re evaluating a fiberglass metering manhole for your project, our experienced engineered sales team is ready to help.
Contact VPC Fiberglass to review your project requirements and find the right solution for your application.
Disclaimer: VPC Fiberglass does not manufacture, distribute, or represent the Teledyne ISCO LaserFlow® product. All references to the LaserFlow® are for compatibility or informational purposes only and are the property of Teledyne ISCO.