Enviro Products: Double Containment & Twin-Wall Pipe Systems
Specialist double containment, twin-wall pipe and flexible chemical-dosing systems
for transporting hazardous, aggressive and environmentally sensitive fluids.
About Enviro Products
The IPS Flow Systems Enviro Products range is designed for industrial and process applications where fluid containment, environmental protection and system integrity are critical.
Double containment pipework uses an inner carrier pipe to transport the fluid and an outer pipe or wall to provide secondary containment. If the carrier pipe leaks, the outer system helps retain the fluid and can support inspection or leak-detection arrangements.
These systems are commonly selected where uncontrolled leaks could affect
employees, equipment, buildings, soil or groundwater.
The IPS range includes rigid pipe-in-pipe systems, integrated twin-wall pipework,
flexible double-contained hose, Copely TPV hose options and fabricated secondary-containment systems for selected above-ground and below-ground installations.
Available materials include PVC-U, PVC-C, polypropylene, polyethylene and PVDF, depending on the selected product and application.
Chemical compatibility, temperature, pressure, installation conditions and monitoring requirements must always be checked before a system or hose is specified.
Explore our Enviro Range
Explore Our Double Containment Pipework Range
IPS Flow Systems supplies double containment, twin-wall and flexible chemical-dosing products for chemical dosing, process waste, fuel transfer and other hazardous-fluid applications.
The range includes:
Each product family has different material, pressure, temperature, installation and monitoring characteristics. The correct system should therefore be selected according to the complete operating duty rather than by diameter alone.
DuoSafe® PVC-U and PVC-C Double Containment
DuoSafe is a rigid pipe-in-pipe system consisting of an inner carrier pipe and a separate outer containment pipe.
Systems are available with PVC-U or PVC-C carrier pipe and a choice of containment materials, depending on the selected configuration. Options may include grey or clear PVC-U, PVC-C, ABS and polyethylene containment.
Clear containment sections can assist with visual inspection of the space between the carrier and containment pipes. However, visible inspection does not replace a designed leak-detection system where continuous monitoring is required.
DuoSafe PVC-U is generally suitable for working temperatures up to approximately 60°C. DuoSafe PVC-C can be considered for higher-temperature applications, potentially up to approximately 100°C.
Final temperature limits depend on the chemical, concentration, pressure, pipe dimensions, jointing method and manufacturer’s technical data.
DuoSafe systems can be used for selected above-ground and below-ground applications, including chemical dosing and the transfer of compatible acids, alcohols, salts and halogens.
Chemical compatibility must be confirmed for the exact fluid, concentration and operating conditions.
DuoSafe® FLEX Double Containment Hose
DuoSafe FLEX is designed for applications requiring long, continuous lengths of small-diameter double-contained hose.
It is particularly suited to chemical-dosing installations where several dosing points are supplied from a central chemical storage or treatment area.
The carrier and containment hoses are manufactured together as a double-contained product. This can reduce the number of joints needed between the chemical source and the dosing point.
Aquachem and Hydrachem carrier-hose options are available for compatible chemical duties.
Selected products can be supplied in long coils, helping installers route dosing lines through complex sites while minimising intermediate connections.
Carrier-hose sizes, pressure ratings, chemical compatibility and fitting requirements vary. All operating limits should be checked against the selected hose before specification.
Copely TPV Flexible Hose
Copely TPV hose provides a flexible option for selected chemical-dosing, water-
treatment and industrial applications.
TPV stands for thermoplastic vulcanizate. TPV materials combine rubber-like
flexibility and durability with the processing characteristics of a thermoplastic. TPV is lighter than conventional rubber alternatives and fully recyclable.
Potential benefits of selected TPV hose constructions include:
- lightweight and flexible handling;
- good durability;
- flexibility at lower temperatures;
- resistance to a range of chemicals;
- suitability for selected water-treatment dosing duties;
- an alternative to conventional rubber hose in appropriate applications.
Copely TPV hose may be used as a carrier hose within an appropriately designed containment arrangement, or as flexible hose where secondary containment is provided separately.
TPV describes the hose material rather than a complete double containment system.
Chemical resistance is application specific. Suitability must be confirmed using:
- the precise chemical;
- concentration;
- operating temperature;
- working pressure;
- continuous or intermittent exposure;
- cleaning conditions;
- fitting and seal materials;
- required service life.
TPV hose should not automatically be treated as suitable for every acid, alkali,
oxidising chemical or solvent.
Poly-Flo® Twin-Wall Pipe Systems
Poly-Flo is an integrated twin-wall piping system manufactured using specially
extruded pipe and injection-moulded twin-wall fittings.
Unlike a conventional double containment system where separate carrier and
containment pipes are assembled together, Poly-Flo combines both walls within a compact product design.
This can reduce the space required for the installation and simplify alignment
between the carrier and containment sections.
Poly-Flo systems are available in polypropylene and PE100-RC options.
Polypropylene systems may suit selected chemical and process applications, while PE100-RC provides a tough polyethylene option with resistance to slow crack growth.
Material compatibility, pressure rating, joining method and environmental conditions should be confirmed for each installation.
AGRUSAFE Double Containment Systems
AGRUSAFE is a fabricated double containment system available in polypropylene and polyethylene material combinations.
The system can be produced across a broad range of carrier and containment sizes, making it suitable for larger or more specialised industrial pipework.
Components may include:
- carrier and containment pipe;
- fittings;
- centralisers;
- support discs;
- fixed-point fittings;
- access points;
- leak-detection connections.
Because AGRUSAFE is fabricated to suit the project, the final design can be
adapted to the pipe size, pressure class, material combination and monitoring
requirements.
The complete installation should be designed and specified as one engineered
arrangement rather than as unrelated inner and outer pipes.
Durapipe P-LX Fuel Pipework
Durapipe P-LX is a fusion-welded, multilayer polyethylene pipe system designed for the transfer of petrol, diesel, fuel oil and compatible biofuels.
The range includes secondary-containment configurations for specialist fuel-transfer applications.
Electrofusion joining is used to create welded connections between the pipe and
fittings.
Selected P-LX arrangements allow the space between the carrier and containment pipe to be tested or monitored for leaks.
Installation suitability differs between configurations. Some polyethylene pipe-in-pipe systems may be suitable for outdoor use, while certain close-fit products are intended specifically for below-ground installation.
The precise system, pressure rating, fuel compatibility, permeability performance and installation environment must be confirmed before selection
AGRUSAFE Sure Grip® Liners
AGRUSAFE Sure Grip liners are thermoplastic concrete-protection products used to create chemically resistant linings for concrete structures and tanks.
They can be incorporated into single-wall or twin-wall lining arrangements,
depending on the design.
Applications can include:
- tanks;
- channels;
- sumps;
- chambers;
- wastewater structures;
- chemically exposed concrete surfaces.
The liner material, anchoring arrangement, welding method and chemical
compatibility should be selected according to the service conditions.
Key Features of IPS Containment Systems
IPS containment systems provide a secondary barrier around pipework carrying
hazardous, aggressive or environmentally sensitive fluids.
The range includes rigid, flexible, integrated twin-wall and fabricated systems,
together with Copely TPV hose options for selected chemical-dosing duties.
Secondary Containment Protection
The outer pipe or wall is designed to help contain fluid if the inner carrier line leaks.
This can reduce the risk of an uncontrolled discharge reaching buildings, equipment, walkways, soil or groundwater.
Secondary containment does not remove the need for correct:
- material selection;
- pressure design;
- installation;
- jointing;
- testing;
- inspection;
- maintenance.
Choice of Thermoplastic Materials
Available system materials include PVC-U, PVC-C, polypropylene, polyethylene and PVDF.
Flexible hose options may also use TPV or other application-specific thermoplastic materials.
Each material provides different chemical, temperature, pressure, mechanical and installation characteristics.
The carrier and containment materials do not always need to be identical, but the complete material combination must be suitable for the intended duty.
Rigid, Flexible and Fabricated Options
Rigid pipe-in-pipe systems are suitable for many fixed process installations.
Integrated twin-wall systems provide a compact alternative to conventional pipe-in-pipe construction.
Flexible double containment hose can reduce the number of joints required along chemical-dosing routes.
Copely TPV hose provides a lightweight and flexible option for selected water-treatment and chemical-dosing applications.
Fabricated systems offer greater flexibility for larger diameters, unusual material combinations and specialist layouts.
The complete system must be checked for chemical compatibility, temperature, pressure, jointing and containment requirements.
Above-Ground and Below-Ground Installation
Selected systems may be installed above or below ground.
However, not every product or configuration is suitable for both environments.
System design should consider:
- ultraviolet resistance;
- external loading;
- impact risk;
- burial depth;
- ground conditions;
- groundwater;
- thermal movement;
- access for inspection;
- future maintenance.
Leak Detection and Monitoring
Selected containment systems can incorporate:
- clear containment sections;
- leak-detection connections;
- monitored interstitial spaces;
- automated leak-detection equipment.
Visible containment can assist with inspection but does not replace electronic monitoring where continuous leak detection is required.
Pressure-Rated System Options
Carrier and containment pipes can have different pressure ratings.
The carrier pipe is selected to transport the process fluid. The outer pipe is selected according to the pressure or containment conditions that could occur following a leak.
Pressure ratings vary according to:
- material;
- temperature;
- diameter;
- wall thickness;
- joining method;
- system type.
Current manufacturer data should always be checked.
Applications for Double Containment & Twin-Wall Pipe
The IPS plastic sheet and rod range is organised by material, helping customers identify a suitable polymer before selecting the required size, thickness, colour or product form. The range includes:
chemical-dosing lines;
flexible TPV dosing-hose installations;
water-treatment dosing systems;
industrial and process-waste pipework;
laboratory waste systems;
pressurised chemical transfer;
bulk chemical storage transfer;
nuclear and decommissioning applications;
petroleum and fuel-transfer systems;
pharmaceutical production;
semiconductor manufacturing;
plating and metal-finishing plants;
chemical-processing facilities;
above-ground process pipework;
below-ground hazardous-fluid transfer;
groundwater-protection applications;
Chemical-Dosing Lines
Chemical-dosing systems often transport concentrated chemicals through small-
diameter pipe or hose.
Double containment provides a second barrier around the dosing line and can help prevent a local leak from reaching equipment, walkways or the surrounding
environment.
Long-length flexible products may be useful where several dosing points are
supplied from one chemical-storage location.
DuoSafe FLEX, Hydrachem and selected Copely TPV hose options allow the
dosing-line material and construction to be chosen according to the chemical,
pressure, temperature, routing and flexibility requirements.
The hose or pipe material must be checked for compatibility with the exact dosing
chemical.
Water Treatment
Water-treatment installations frequently use chemicals for:
- pH adjustment;
- disinfection;
- coagulation;
- chlorination;
- odour control;
- other treatment processes.
Rigid pipe, double-contained hose and selected Copely TPV hose products may be considered for compatible dosing duties.
The proposed product must be checked against the chemical concentration,
operating temperature, pressure, dosing frequency and cleaning regime.
Chemical and Industrial Processing
Chemical and industrial plants may require double containment around process
chemicals, hazardous waste, aggressive liquids and sensitive transfer lines.
Rigid pipe-in-pipe, twin-wall and fabricated systems provide different options
depending on the pipe size, process pressure and installation layout.
Flexible hose may be appropriate for certain dosing, equipment-connection or
difficult-routing applications.
Fuel Transfer
Specialist fuel systems can be used for the controlled transfer of petrol, diesel, fuel oil and compatible biofuels.
Fuel compatibility, permeability, fire strategy, installation environment and leak
monitoring require system-specific assessment.
A general chemical double containment pipe or flexible hose should not
automatically be used for fuel service.
Pharmaceutical and Semiconductor Applications
Pharmaceutical and semiconductor facilities may require containment around
chemical-distribution, waste or process lines.
Material purity, cleanability, extractables, leak detection and installation quality may be as important as chemical resistance.
Where PVDF or another high-performance material is being considered, the precise grade and purity requirement must be specified
Why Choose IPS Flow Systems for Enviro Products?
IPS Flow Systems supplies double containment, twin-wall, flexible hose and specialist environmental-protection systems for demanding industrial applications.
The range covers:
small flexible dosing lines;
Copely TPV hose options;
rigid chemical pipework;
integrated twin-wall systems;
fabricated large-diameter containment;
specialist fuel-transfer products.
fluid and concentration;
required flow rate;
containment design;
required flexibility;
joining or hose-connection method;
temperature and pressure;
carrier-pipe or hose dimensions;
material compatibility;
installation location;
leak detection;
inspection and maintenance requirements.
Our Partners & Brands in Enviro Products
IPS Flow Systems supplies specialist containment and chemical-dosing products from established thermoplastic piping, hose and environmental-protection ranges.
The portfolio includes:
DuoSafe®;
DuoSafe® FLEX;
Poly-Flo®;
AGRUSAFE;
Durapipe P-LX;
AGRUSAFE Sure Grip®;
Copely TPV hose options;
Aquachem and Hydrachem hose options.
Each range supports different applications, from small chemical-dosing lines to large fabricated containment systems and specialist fuel-transfer pipework.
Current availability, dimensions, working pressure, temperature limits and chemical compatibility should be confirmed before specification.
Enviro Products Technical Resources
IPS provides product information, technical guidance and downloadable resources for the Enviro Products range.
These resources can help engineers, contractors and purchasing teams compare:
system type;
carrier and containment materials;
TPV and other flexible-hose options;
pipe or hose dimensions;
pressure ratings;
temperature limits;
joining and connection methods;
leak-detection options;
above-ground and below-ground suitability.
Project-specific technical review is recommended where hazardous, environmentally sensitive or high-consequence fluids are involved.
The Ultimate Guide to Double Containment
Download the IPS guide to double containment pipework for an overview of system types, material options and selection considerations.
Hydrachem Double Containment Hose
Download the technical flyer for Hydrachem double-contained hose and associated chemical-dosing applications.
About DuoSafe®
Learn more about rigid PVC-U and PVC-C DuoSafe pipe-in-pipe systems.
About DuoSafe® FLEX
Learn more about flexible double containment hose for chemical-dosing lines.
About Poly-Flo®
Learn more about Poly-Flo polypropylene and PE100-RC twin-wall systems.
About AGRUSAFE
Learn more about fabricated polypropylene and polyethylene AGRUSAFE double containment systems.
Enviro Products Handbook
Download the Enviro Products section of the IPS handbook for system information, dimensions, product codes and available components.
Enviro Products Handbook in Euro Format
Download the Euro version of the Enviro Products handbook section for the same product information in a euro pricing format.
Frequently Asked Questions
What is a double-wall pipe?
A double-wall pipe system has an inner carrier pipe and an outer containment pipe or wall. The carrier pipe transports the process fluid. The outer pipe provides secondary containment if the carrier system leaks. The space between the two pipes is commonly called the interstitial or annular space. It can be used for inspection, testing or leak monitoring.
What is twin-wall pipe?
In containment applications, twin-wall pipe has two integrated walls that provide carrier and secondary-containment functions within one manufactured product.
This differs from a conventional pipe-in-pipe system, where separate inner and outer pipes are assembled together.
Poly-Flo is an example of an integrated twin-wall thermoplastic system.
What is the difference between double-wall and double containment pipe?
The terms are often used interchangeably, but they can describe different constructions.
Double containment is the general principle of placing a secondary barrier around the carrier pipe.
A double-wall or twin-wall product may incorporate both walls into one manufactured pipe. A pipe-in-pipe system uses separate carrier and containment components.
How do I choose the correct double containment pipe size?
Begin by sizing the inner carrier pipe for the required flow rate, velocity, pressure and process duty.
The outer containment size must provide adequate space for:
- fittings and centralisers;
- thermal movement;
- drainage or leak flow;
- inspection;
- leak-detection equipment;
- installation and jointing.
Material compatibility, pressure, temperature and installation conditions must also be considered.
Does every double containment system include leak detection?
No. Some systems include clear containment sections, test ports or leak-detection connections. Others can be connected to separate monitoring equipment. The required level of monitoring should be defined during system design.
Can double containment pipe be installed underground?
Selected systems can be installed below ground, but underground suitability is
product and configuration dependent.
The design must account for:
- soil loading;
- burial depth;
- groundwater;
- vehicle loading;
- jointing;
- access;
- leak monitoring;
- future maintenance.
Which materials are available for double containment pipe?
The IPS range includes systems using PVC-U, PVC-C, polypropylene, polyethylene
and PVDF.
Flexible carrier-hose options may also use materials such as TPV.
The best material depends on the chemical, concentration, temperature, pressure, purity requirements and installation environment.
What is Copely TPV hose?
TPV stands for thermoplastic vulcanizate.
It is a high-performance thermoplastic elastomer that provides many rubber-like flexibility and durability characteristics while being lighter and recyclable.
Selected Copely TPV hose products may be considered for water-treatment, chemical-dosing and other industrial applications where their precise construction is compatible with the duty.
Can Copely TPV hose be used for every dosing chemical?
No.
No hose material should be assumed to suit every dosing chemical.
Selection must consider:
- the chemical name;
- concentration;
- operating temperature;
- cleaning temperature;
- working pressure;
- continuous or intermittent exposure;
- hose reinforcement;
- fitting and seal materials;
- permeation risk;
- required service life.
Current chemical-compatibility and product data should be checked before specification.
Is Copely TPV hose a double containment system?
Not by itself.
TPV describes the hose material rather than the complete containment design. It can be supplied as double containment with a clear PVC-U outer or as a single hose if secondary containment is not required. Other containment options are available on request.
