Manufacturer, Supplier & Exporter of PU + Epoxy Coated Pipes for Subsea Use

PU + Epoxy coated pipes for subsea use are steel pipes (typically carbon steel or line‑pipe grades) that incorporate a dual or hybrid external protective system: first an epoxy coating for anti‑corrosion and adhesion, followed by or combined with a polyurethane (PU) outer layer which provides abrasion resistance, flexibility and mechanical protection in underwater or deep‑water conditions. The combination of epoxy + PU makes these pipes particularly suitable for subsea environments where both corrosion and mechanical damage (from sea currents, seabed rocks, marine growth, etc.) are concerns...

Riddhi Siddhi Impex, as a manufacturer and supplier of specialty coated pipes, positions itself to deliver such PU + Epoxy coated subsea pipes in the Indian market. Their manufacturing process would involve selecting appropriate steel pipe substrates (ASTM A106, API 5L, or equivalent), preparing the substrate via blast cleaning, applying the epoxy coating (often via powder or liquid epoxy systems), then applying a polyurethane outer coat which may serve as additional mechanical protection and sometimes thermal insulation in underwater service. This allows the company to cater to demanding infrastructural and offshore projects..

The epoxy inner coating layer ensures excellent adhesion to steel and effective corrosion control in saltwater or aggressive marine environments. The polyurethane outer layer adds flexibility, abrasion resistance (from seabed contact or marine debris), and protects the epoxy layer and steel from mechanical damage and marine conditions. Together, the PU + Epoxy system offers longer service life, reduced maintenance frequency, and improved reliability for subsea pipelines and flowlines..

These coated pipes are primarily intended for subsea pipelines, risers, flowlines, umbilicals, subsea manifolds, port and jetty pipelines, and outfalls. In the Indian context, where offshore fields, coastal industrial zones and port installations are increasing, PU + Epoxy coated pipes can be specified for sea‑bed installations, near‑shore discharge pipelines, submarine power/utility conduits, and deep‑water service where transportation of hydrocarbons, chemicals or seawater is involved...

Riddhi Siddhi Impex supplies these specialty coated pipes across a wide network of Indian cities. Their domestic reach includes major metro and industrial hubs such as Mumbai, Delhi, Bengaluru (Bangalore), Hyderabad, Chennai, Kolkata, Pune, Ahmedabad, Surat, Vadodara, Rajkot; as well as further inland and coastal cities such as Nagpur, Indore, Bhopal, Jaipur, Kanpur, Lucknow, Agra, Varanasi, Amritsar, Chandigarh, Mysuru (Mysore), Udaipur, Jodhpur, Visakhapatnam, Coimbatore, Madurai, Kochi, Thiruvananthapuram, Mangalore, Nashik, Kolhapur, Chandrapur, Akola, Vilayat, Somnath, Dahej, Navsari, Valsad, Rajpipla, Narmada. This extensive coverage means that clients in both coastal and inland locations can access these coated pipe systems..

PU + Epoxy Coated Pipes for Subsea Use

Specification

Product Name	PU + Epoxy Coated Pipes
Manufacturer	Riddhi Siddhi Impex
Base Material	Carbon Steel / Line Pipe (ASTM A106 / API 5L)
Coating Material	Epoxy + Polyurethane (PU)
Standard	ISO, ASTM, API, NACE, EN
Size Range	1/2" NB to 48" NB
Wall Thickness	Sch 20 to Sch 160 / XXS
Length	Single Random, Double Random, or Cut Lengths
Coating Thickness	Epoxy: 150-300 μm, PU: 2-6 mm (Customizable)
Pipe Ends	Plain End (PE), Beveled End (BE), or Threaded
Form	Seamless, Welded, ERW, or LSAW
Applications	Subsea pipelines, flowlines, risers, offshore and marine projects

Chemical Composition (Base Carbon Steel)

Element	Content (%)
Carbon (C)	0.23 Max
Manganese (Mn)	0.30 – 1.06
Phosphorus (P)	0.05 Max
Sulfur (S)	0.045 Max
Silicon (Si)	0.10 – 0.35
Copper (Cu)	0.40 Max
Nickel (Ni)	0.40 Max
Chromium (Cr)	0.40 Max

Mechanical Properties

Property	Value
Tensile Strength	≥ 415 MPa
Yield Strength (0.2% offset)	≥ 240 MPa
Elongation	≥ 20%
Hardness	≤ 95 HRB
Impact Resistance	Excellent (Epoxy + PU Coating)
Coating Adhesion	Strong Adhesion per ISO / NACE standards

Dimension Chart (Nominal)

Nominal Pipe Size (NB)	Outside Diameter (mm)	Wall Thickness (mm)	Length
1/2"	21.3	2.77	Up to 12 m
1"	33.4	3.38	Up to 12 m
2"	60.3	3.91	Up to 12 m
4"	114.3	6.02	Up to 12 m
6"	168.3	7.11	Up to 12 m
10"	273.1	9.27	Up to 12 m
16"	406.4	12.70	Up to 12 m

Equivalent Grades

Standard	Grade
ASTM	A106 Grade B / A53 Grade B
API	5L Grade B / X42 / X52
EN	EN 10216 / EN 10224
DIN	St 37.2 / St 52.3
BS	3601 / 3602

Equivalent Standards

Standard	Description
ASTM A106 / A53	Carbon Steel Pipe for High-Temperature and Pressure Service
API 5L	Line Pipe Specification
ISO / NACE	External PU + Epoxy Coating Standards for Subsea Pipes

Other Types of Coated Pipes

Type	Description
3LPE Coated Pipes	Three-layer polyethylene coated pipes for corrosion protection
FBE Coated Pipes	Fusion Bonded Epoxy coated pipes for adhesion & corrosion resistance
Internal Epoxy Coated Pipes	Epoxy coated internal surfaces for smooth fluid flow
PE Coated Pipes	Polyethylene coated carbon steel pipes for underground applications

Because subsea quality coated pipes are often large diameter, heavy wall and sheet‑coated, logistics and inventory are critical. Riddhi Siddhi Impex’s domestic presence enables them to arrange manufacturing, coating, testing and shipping to port/shipyard projects (for example Kochi, Visakhapatnam, Mangalore, Dahej) as well as inland fabrication yards (e.g., Kanpur, Indore, Nagpur). They provide stock or project‑specific manufacturing, transportation and ensure coated pipe integrity until installation..

Frequently Asked Questions (FAQs)

Q1: What are the main applications of PU + Epoxy Coated Pipes?

A1: These pipes are used for subsea pipelines, flowlines, risers, offshore and marine projects.

Q2: Can custom coating thicknesses be provided?

A2: Yes, both epoxy and PU coating thickness can be customized according to project requirements.

Q3: Are PU + Epoxy Coated Pipes suitable for deepwater installations?

A3: Yes, the dual coating provides corrosion protection and mechanical resistance required for deepwater subsea pipelines.

Q4: Which Indian cities are served by Riddhi Siddhi Impex?

A4: The company supplies pipes across Mumbai, Delhi, Bengaluru, Hyderabad, Chennai, Kolkata, Pune, Ahmedabad, Surat, Vadodara, and more inland & coastal cities.