Hydroformed MLP for Geothermal

Engineered efficiency

Corrosion resistance where it matters

Geothermal pipework can face high temperatures, chlorides, dissolved CO₂ and H₂S, low pH, oxygen ingress, solids and repeated thermal cycling.

Proclad MLP places the selected corrosion-resistant alloy at the wetted surface, while a carbon-steel host provides structural strength.

01 · OUTER STRUCTURE

Carbon-steel host

Selected to meet the project design basis, fabrication route and mechanical loads.

02 · WETTED SURFACE

CRA liner

Matched to the actual fluid chemistry, temperature and corrosion mechanisms.

03 · ENGINEERED INTERFACE

Hydroformed liner fit

Controlled hydraulic expansion presses the CRA liner against the carbon-steel host. The liner provides the wetted surface while the host carries structural loads.

Geothermal duty

Materials selection for the full operating cycle

Materials must be selected for the complete operating envelope: start-up, steady state, shut-down, cleaning, oxygen ingress and upset conditions.

Temperature

High-enthalpy fluid, steam and thermal cycling

Chemistry

Chlorides, CO₂, H₂S, acidity and dissolved oxygen

Flow

Two-phase behaviour, velocity, erosion and solids

Lifecycle

Corrosion allowance, inspection and intervention strategy

Across the surface system

From well pad to reinjection

Surface piping applications, subject to service-specific materials selection and qualification.

01 · Production and gathering lines

Corrosion-resistant transport from the well pad to separation and processing facilities.

02 · Two-phase flow and brine handling

A CRA wetted surface for high-temperature fluids containing chlorides, CO₂, H₂S and other corrosive species.

03 · Steam and condensate piping

Engineered protection for selected above-ground plant and balance-of-plant pipework.

04 · Reinjection systems

CRA-lined pipe for reinjection headers and brine return lines, with materials selected for fluid chemistry, temperature and oxygen exposure.

Materials flexibility

Select the liner for the fluid

Proclad can support a broad range of CRA liner grades. The right choice depends on the complete chemistry and operating envelope, including oxygen ingress and upset conditions.

Request a geothermal materials review

01
Nickel-base alloys
Options including Alloy 625 and Alloy 825 for demanding combinations of temperature, chlorides and acidic gases.

02
Austenitic stainless steels
Grades such as 904L and 6Mo for appropriate brine and process conditions.

03
Duplex & super duplex
High-strength, corrosion-resistant options where chemistry, temperature and fabrication requirements align.

Qualification

Qualification for your piping package

To help Proclad recommend the right solution, please share your fluid analysis along with normal operating and upset temperatures, pressure conditions, pipe sizes, and joining requirements.

Our technical team will work with your project team to review the materials basis and confirm the product evidence, inspection scope, and service-specific testing needed for the application.

This ensures the selected solution is supported by qualification and documentation appropriate to its intended service.

This guidance applies to surface pipework only. Downhole tubing and casing are subject to different operating conditions and require a separate qualification review.

Hydroformed MLP for geothermal — FAQs

When should hydroformed MLP be considered instead of solid CRA pipe or weld overlay

MLP places the selected corrosion-resistant alloy at the wetted surface while the carbon-steel host carries structural loads. Compared with solid CRA pipe, this can reduce the volume of alloy required and improve material efficiency. Weld overlay applies a corrosion-resistant layer by welding. The right option depends on fluid chemistry, pipe dimensions, fabrication, joining, inspection and project qualification requirements.

How is the CRA liner selected for geothermal service?

Liner selection is based on the complete operating envelope—not temperature or chloride content alone. The review should consider pH, CO₂, H₂S, dissolved oxygen, solids, flow regime, start-up, shut-down, cleaning and upset conditions. Nickel-base alloys, austenitic stainless steels, duplex and super-duplex grades can then be assessed against the identified corrosion mechanisms.

How are pipe ends and field joints addressed?

Pipe-end preparation and the proposed joining method should be considered as part of the piping-package design. Proclad can review pipe dimensions, field-joint requirements, fabrication route, inspection needs and any transition or termination details as part of the project qualification plan.

What qualification and product evidence can be provided?

The required evidence is defined for the specific service and project specification. This may include materials traceability, dimensional inspection, non-destructive examination, manufacturing records and service-specific testing. Proclad can agree the required inspection and qualification package with the project team.

What information is needed to start a geothermal materials review?

Provide the available fluid analysis, operating and upset temperatures, pressure, flow regime, pipe sizes, design life and joining requirements. Include chloride content, pH, dissolved gases, solids and oxygen exposure where known. Proclad can identify missing information and define the next stage of the assessment.

Does this cover downhole tubing and casing?

This page addresses geothermal surface pipework, including gathering lines, brine handling, steam and condensate piping, and reinjection systems. Downhole tubing and casing need a separate application and qualification review.