SMC VCZ Series Circulating Fluid Valves: VCZW31-5G-15-04-J-X21 0190-11558

Technical Dossier

Product Details And Specifications

SMC VCZ Series: Comprehensive Circulating Fluid Valve Range and Technical Overview

The SMC VCZ series is a dedicated line of 2-port solenoid valves engineered for coolant and circulating fluid control in precision machining, semiconductor fabrication, chemical processing, and industrial automation environments. Deployed across CNC machining centers, cooling towers, and process fluid circuits in petrochemical refineries, nuclear facility auxiliary systems, and heavy manufacturing plants, the VCZ series occupies a critical position in fluid management infrastructure globally. Its compact body design, broad media compatibility (water, cutting oil, coolant, mild chemicals), and direct-acting or pilot-operated configurations make it a standard specification component in OEM machine tool builds and plant maintenance BOMs worldwide.

The Evolution of VCZ Series Architecture

SMC introduced the VCZ series as a successor to earlier general-purpose solenoid valve lines, specifically optimizing the internal flow path geometry for low-viscosity fluid media such as water-soluble coolants and cutting fluids. Early VCZ variants used a single-coil direct-acting mechanism suited for low-pressure, low-flow applications (Rc 1/8 to Rc 1/4 port sizes). As industrial demand scaled, SMC expanded the series to include pilot-operated configurations capable of handling higher flow rates at Rc 3/8 and Rc 1/2 port sizes, while maintaining the same DIN-standard coil interface for backward compatibility.

The introduction of the VCZW sub-series brought a watertight (IP65) coil enclosure, addressing field failures caused by coolant splash in open machine tool environments. Subsequent revisions added lead wire options (standard vs. DIN connector), voltage variants (AC 100V, AC 200V, DC 12V, DC 24V), and orifice diameter options to fine-tune Cv values for specific circuit designs. The series has reached maturity; SMC continues to manufacture and support VCZ components, but design evolution has stabilized. Long-term maintenance planning should account for coil and seal kit availability as the primary consumable replacement strategy.

VCZ Series Full Catalog & Functionalities (SKU List)

The following SKUs represent the documented VCZ series range, categorized by configuration type. Each model is a distinct, verified part number within the SMC VCZ product family.

Direct-Acting, Standard Body (Rc 1/8 – Rc 1/4)

• VCZW21-5D-6-04: Direct-acting, Rc 1/4, orifice 6 mm, DC 24V coil, watertight enclosure, standard lead wire.
• VCZW21-5D-6-06: Direct-acting, Rc 3/8, orifice 6 mm, DC 24V coil, watertight enclosure, standard lead wire.
• VCZW21-5G-6-04: Direct-acting, Rc 1/4, orifice 6 mm, AC 100V coil, watertight enclosure, standard lead wire.
• VCZW21-5G-6-06: Direct-acting, Rc 3/8, orifice 6 mm, AC 100V coil, watertight enclosure, standard lead wire.
• VCZW21-5L-6-04: Direct-acting, Rc 1/4, orifice 6 mm, AC 200V coil, watertight enclosure, standard lead wire.

Pilot-Operated, Large Body (Rc 3/8 – Rc 1/2)

• VCZW31-5D-15-04: Pilot-operated, Rc 1/4, orifice 15 mm, DC 24V coil, watertight enclosure, standard lead wire.
• VCZW31-5D-15-06: Pilot-operated, Rc 3/8, orifice 15 mm, DC 24V coil, watertight enclosure, standard lead wire.
• VCZW31-5G-15-04: Pilot-operated, Rc 1/4, orifice 15 mm, AC 100V coil, watertight enclosure, standard lead wire.
• VCZW31-5G-15-06: Pilot-operated, Rc 3/8, orifice 15 mm, AC 100V coil, watertight enclosure, standard lead wire.
• VCZW31-5G-15-04-J: Pilot-operated, Rc 1/4, orifice 15 mm, AC 100V coil, watertight, DIN connector terminal.
• VCZW31-5G-15-04-J-X21: Pilot-operated, Rc 1/4, orifice 15 mm, AC 100V, DIN connector, special specification X21 (extended lead wire / modified coil housing).
• VCZW31-5G-15-04-J-X21 0190-11558: Factory-assigned lot/revision code 0190-11558; functionally identical to base VCZW31-5G-15-04-J-X21, used for traceability in OEM machine tool builds.
• VCZW31-5L-15-04: Pilot-operated, Rc 1/4, orifice 15 mm, AC 200V coil, watertight enclosure, standard lead wire.
• VCZW31-5L-15-06: Pilot-operated, Rc 3/8, orifice 15 mm, AC 200V coil, watertight enclosure, standard lead wire.
• VCZW31-5D-15-06-J: Pilot-operated, Rc 3/8, orifice 15 mm, DC 24V coil, watertight, DIN connector terminal.
• VCZW21-5D-6-04-J: Direct-acting, Rc 1/4, orifice 6 mm, DC 24V coil, watertight, DIN connector terminal.
• VCZW21-5G-6-06-J: Direct-acting, Rc 3/8, orifice 6 mm, AC 100V coil, watertight, DIN connector terminal.

Sourcing Hard-to-Find & Obsolete VCZ Series Parts

DriveKNMS maintains a dedicated inventory program for SMC VCZ series components, with particular focus on special-specification variants (X21, X22, X-series suffixes) and OEM-coded lot numbers such as 0190-11558 that are not available through standard distribution channels. These part numbers are frequently embedded in machine tool BOMs from Japanese and European CNC manufacturers and become critical single-point-of-failure items during unplanned downtime events.

Our sourcing process covers: verified surplus stock from decommissioned production lines, cross-referencing OEM lot codes to standard SMC catalog numbers, and direct procurement from SMC-authorized regional distributors in Japan, Germany, and the United States. For discontinued coil assemblies and seal kits, DriveKNMS provides compatibility mapping to current SMC replacement part numbers, enabling maintenance teams to execute like-for-like replacements without engineering change orders.

Response time for VCZ series inquiries: standard stock items ship within 2 business days; special-specification and lot-coded variants are quoted within 24 hours of inquiry receipt.

Quality Control for the VCZ Series Range

SMC VCZ valves present specific inspection requirements due to their fluid-contact internal components and IP65-rated coil assemblies. DriveKNMS applies the following test protocol to all VCZ units processed through our facility:

• Coil resistance verification: Measured against SMC published nominal values per voltage variant (DC 24V, AC 100V, AC 200V). Deviation beyond ±10% triggers coil rejection.
• Insulation resistance test: 500V DC megohm test between coil terminals and valve body. Minimum acceptance threshold: 100 MΩ.
• Leak test: Pressurized to rated working pressure (0.1–0.8 MPa range per model) with fluid-side ports sealed. Zero external leakage tolerance.
• Actuation cycle test: Minimum 50 open/close cycles under rated voltage to confirm plunger and spring mechanism integrity.
• DIN connector interface check: For J-suffix models, connector locking mechanism and pin contact resistance verified per EN 175301-803 standard.
• Seal condition inspection: NBR or EPDM seals inspected under magnification for compression set, cracking, or media degradation.

All units are tagged with inspection date, technician ID, and test results prior to dispatch. Test records are retained for 3 years and available upon request.