Khớp nối linh hoạt style D/DS

The Piedmont Style D/DS flexible coupling is a premium product line designed to meet the stringent requirements of industrial piping systems, especially high-pressure RO water treatment systems for seawater desalination. Manufactured from Duplex and Super Duplex stainless steel with outstanding corrosion resistance, the coupling is capable of withstanding working pressures up to 1200 psi, ensuring high reliability and superior performance even in harsh operating environments.

Brand: Piedmont

Product Type: Couplings

PRODUCT FEATURES

Maximum working pressure up to 1200 psi (82 bar) when used with schedule 40s pipes with cut grooves.
Housing made of Duplex stainless steel CE8MN or Super Duplex stainless steel CE3MN, providing excellent resistance to corrosion and suitability for seawater and chemical environments.
Dual-phase Austenite-Ferrite structure, delivering enhanced mechanical properties and approximately twice the strength of 316L stainless steel.
EPDM gasket compliant with NSF/ANSI 61, suitable for hot and cold water; peroxide-cured EPDM available for special applications.
316 stainless steel bolts with silicon bronze nuts (¾”-3”) or 316 stainless steel nuts (4” and above), manufactured in accordance with ASTM F-593/F-594 and DIN standards.
Optional anti-corrosion protective coatings available upon request, including epoxy-polyurethane or fluoropolymers such as Xylan and Fluorokote.
Flexible connection design, easy installation and maintenance, suitable for cut-grooved piping systems.
Materials meet PREN >35 (Duplex) and PREN >40 (Super Duplex), offering excellent resistance to pitting and crevice corrosion.

SPECIFICATIONS

Nominal size

3/4 – 12 inch
Outside diameter

1.91 – 15.28 inch (48.5 – 388.1 mm)
Length

3.04 – 17.38 inch (77.2 – 441.4 mm)
Height

1.68 – 2.55 inch (42.7 – 64.8 mm)
Approx. weight

0.81 – 34.82 lb (0.37 – 15.8 kg)
Working pressure

1200 psi (82 bar)

The Style D/DS flexible coupling is an advanced solution for piping systems that require high strength, stable operation, and safe performance under high pressure and highly corrosive conditions. With an optimized design, premium materials, and internationally recognized certifications, the product is suitable for a wide range of industrial applications.

1. Specification of Piedmont Style D/DS flexible coupling

The Piedmont Style D/DS flexible coupling features robust specifications that ensure stable operation even under high-pressure conditions. Designed to meet the demanding requirements of industrial piping systems, this coupling provides a reliable connection solution for water and desalination industries.

NOMINAL SIZE	OUTSIDE DIAMETER	LENGTH	HEIGHT	APPROX. WEIGHT	PRESSURE RATING
¾ inch	1.91 inch (48.5 mm)	3.04 inch (77.2 mm)	1.68 inch (42.7 mm)	0.81 lb (0.37 kg)	1200 psi (82 bar)
1 inch	2.29 inch (58.2 mm)	3.42 inch (86.9 mm)	1.68 inch (42.7 mm)	0.97 lb (0.44 kg)
1¼ inch	2.5 inch (63.5 mm)	3.65 inch (92.7 mm)	1.71 inch (43.4 mm)	1.08 lb (0.49 kg)
1½ inch	2.76 inch (70.1 mm)	4.06 inch (103.1 mm)	1.71 inch (43.4 mm)	1.21 lb (0.55 kg)
2 inch	3.24 inch (82.3 mm)	4.38 inch (111.3 mm)	1.85 inch (47 mm)	1.92 lb (0.87 kg)
2½ inch	3.74 inch (95 mm)	5.3 inch (134.6 mm)	1.85 inch (47 mm)	2.14 (0.97 kg)
3 inch	4.48 inch (113.8 mm)	6.03 inch (153.2 mm)	1.85 inch (47 mm)	2.64 lb (1.2 kg)
4 inch	5.7 inch (144.8 mm)	7.6 inch (193 mm)	2.02 inch (51.3 mm)	4.54 lb (2.06 kg)
5 inch	7.22 inch (183.4 mm)	9.5 inch (241.5 mm)	2.02 inch (51.3 mm)	9.3 lb (4.23 kg)
6 inch	8.18 inch (207.9 mm)	10.25 inch (260.4 mm)	2.02 inch (51.3 mm)	9.74 lb (4.42 kg)
8 inch	10.89 inch (276.6 mm)	13.44 inch (341.5 mm)	2.34 inch (60.7 mm)	24.5 lb (11.11 kg)
10 inch	13.28 inch (337.3 mm)	15.88 inch (403.3 mm)	2.55 inch (64.8 mm)	33.46 lb (15.18 kg)	1000 psi (69 bar)
12 inch	15.28 inch (388.1 mm)	17.38 inch (441.4 mm)	2.55 inch (64.8 mm)	34.82 lb (15.8 kg)	1000 psi (69 bar)

2. Key features of Piedmont Style D/DS flexible coupling

The Piedmont Style D/DS flexible coupling stands out with advanced technical features that ensure exceptional performance and reliability in high-pressure water applications and highly corrosive environments:

Maximum working pressure: Up to 1200 psi (82 bar) with schedule 40s cut-grooved pipes, applicable to all sizes.
Housing material: Duplex stainless steel CE8MN (ASTM A-890 Gr.2A) or Super Duplex stainless steel CE3MN (Gr.5A), offering excellent corrosion resistance, particularly in seawater, brackish water, and chemical environments.
Superior mechanical properties: Duplex alloys feature a dual-phase Austenite-Ferrite microstructure, providing approximately twice the tensile strength of conventional 316L stainless steel.
EPDM gasket: NSF/ANSI 61 certified, suitable for hot and cold water, available in C-shaped and Flush-fit designs; peroxide-cured EPDM available for special applications such as chloramine environments.
Bolts and nuts: 316 stainless steel or silicon bronze (for sizes ≤ 3 inch), manufactured in accordance with ASTM F-593/F-594, DIN 934, DIN 931/933.
Optional external coatings: Coupling housings can be supplied with epoxy primer and polyurethane topcoat; fasteners may be coated with fluoropolymers such as Xylan or Fluorokote for oil & gas applications.
High compatibility: Suitable for standard cut-grooved piping systems; easy installation, maintenance, and operation.
International material standards: PREN >35 for Duplex and PREN >40 for Super Duplex, ensuring excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.

3. Advantages of Piedmont Style D/DS flexible coupling

The Style D/DS pipe coupling is distinguished by its high-pressure capability, outstanding mechanical strength, and superior corrosion resistance in harsh industrial environments:

Withstands working pressures up to 1200 psi (82 bar), ideal for seawater RO systems and heavy-duty industrial applications.
Duplex and Super Duplex materials provide double the tensile strength compared to 316L stainless steel.
Exceptional corrosion resistance in seawater, brackish water, and aggressive chemical environments.
NSF/ANSI 61-certified EPDM gasket, with optional peroxide-cured EPDM for special service conditions.
Suitable for standard cut-grooved piping systems, enabling fast installation and easy maintenance.
Optional anti-corrosion coatings (epoxy-polyurethane for housings, fluoropolymer for fasteners) to extend service life.
Multiple bolt and nut material options, from 316 stainless steel to silicon bronze, meeting diverse technical requirements.
All materials comply with strict international standards such as ASTM and DIN, ensuring long-term reliability.

4. Quality standards of Piedmont Style D/DS flexible coupling

One of the key factors behind the reputation of Piedmont Style D/DS grooved couplings is the strict quality control system certified by internationally recognized organizations. These standards ensure not only technical compliance but also long-term stable performance:

ISO 9001:2015 certification for quality management system.
EN 10204 3.1 certificates for metallic components (housing, bolts, nuts).
EN 10204 2.2 certificates for EPDM gaskets.
EN 10204 2.1 certificates for purchase orders (PO).

Additional independent inspection and testing can be provided upon request, including:

Hydrostatic pressure testing at 1.5 times working pressure (ASTM F1476, ANSI AWWA C606).
Positive Material Identification (PMI) by X-ray fluorescence.
Metallurgical and microstructural analysis, including ferrite content (ASTM E562).
Corrosion testing (ASTM G48, ASTM A923, ASTM A262).
Hardness testing (ASTM A370), impact testing (Charpy), dye penetrant testing (DPT), and crevice corrosion testing (Ferroxyl).
Independent certification such as EN 10204 3.2 by GIS, SGS, Bureau Veritas.
Materials are manufactured in accordance with ASTM A1082 (Duplex 2205 PREN >35, Super Duplex PREN >40).
EPDM gaskets are NSF/ANSI 61 certified for drinking water applications.
Bolts, nuts, and washers comply with ASTM F-593/F-594, DIN 934/931/933, DIN 125.

5. Applications of Piedmont Style D/DS flexible coupling

The Piedmont Style D/DS flexible coupling is widely used not only in high-pressure systems but also in applications with severe cyclic loading, such as areas near positive displacement piston pump outlets or energy recovery devices in seawater desalination plants.

In industrial facilities and desalination systems, grooved couplings are subjected to repeated loads caused by vibration and axial displacement. This requires robust mechanical design and materials with high corrosion resistance and strength.

The Style D/DS coupling with Duplex/Super Duplex construction is an ideal solution for:

High-pressure seawater RO (SWRO) systems with demanding operating cycles.
Feed, recovery, and discharge systems in ultrafiltration (UF) and microfiltration (MF) skids.
Energy recovery systems in the water industry.
Applications in oil & gas, chemical processing, and harsh water treatment environments.

6. Authorized supplier of Piedmont Style D/DS flexible coupling in Vietnam

Selecting the right distributor is critical to ensure product quality and proper technical support. ATS Water Technology Co., Ltd. is the authorized distributor of Piedmont couplings in Vietnam, including the Duplex/Super Duplex Style D/DS series—an optimal solution for high-pressure and corrosive environments.

With extensive experience in water treatment and industrial equipment supply, ATS Water Technology provides genuine products along with technical consulting, system design solutions, and complete product documentation. All supplied products ensure clear traceability, fast after-sales support, and full technical compliance.

Please contact ATS Water Technology Co., Ltd. for professional consultation and to select the most suitable flexible coupling for your system.

ATS WATER TECHNOLOGY CO., LTD