Product Overview
The NUPRO SS-4BMG is a precision bellows-sealed metering valve engineered by Swagelok for accurate, repeatable flow control in high-purity and demanding process systems. Unlike diaphragm or packed-stem designs, this valve utilizes a welded metal bellows as the primary sealing element, isolating the process media from the atmosphere and eliminating stem leakage paths. The SS-4BMG features a 1/4 in. Swagelok tube fitting connection and a 316 stainless steel body, making it suitable for corrosive, toxic, or expensive fluids where zero leakage and fine adjustment resolution are critical. Its non-rising stem design with a calibrated micrometer-style handle allows operators to set and reproduce flow rates with high precision, serving as an essential control component in analyzer systems, sampling panels, and pilot-scale process loops.
Technical Specifications
| Parameter | Specification / Feature |
|---|---|
| Component Type | Bellows-Sealed Metering Valve (Process & Pneumatic Valve) |
| Model Designation | SS-4BMG |
| Body Material | 316 Stainless Steel |
| End Connection | 1/4 in. Swagelok Tube Fitting |
| Sealing Principle | Welded Metal Bellows (leak-tight stem seal) |
| Operating Pressure | Up to 1000 psig (69 bar) at ambient temperature |
| Operating Temperature | -20°F to 900°F (-28°C to 482°C) depending on packing |
| Flow Coefficient (Cv) | 0.03 (fine metering) |
| Mounting & Connection | Panel mountable, Swagelok tube fitting interface |
Engineering Features & Advantages
- Precision Metering Performance: The non-rising stem with a calibrated handle allows fine, repeatable adjustment of flow, enabling accurate setting of low flow rates for analytical and sampling applications.
- Hermetic Bellows Seal: A welded metal bellows provides a leak-tight barrier between the process fluid and the environment, eliminating stem leakage and making the valve ideal for toxic, hazardous, or high-purity media.
- Industrial Reliability: Constructed from 316 stainless steel with a robust stem and seat design, the SS-4BMG is built for continuous service in severe process environments.
- Direct Fit Replacement: Exact dimensional and functional compatibility with original NUPRO SS-4BMG specifications, ensuring drop-in replacement without system modification.
- Direct Fit Replacement: Precision-manufactured to original NUPRO specifications for direct replacement, minimising downtime and eliminating fitment issues.
Typical Industrial Applications
Its non-rising stem design with a calibrated micrometer-style handle allows operators to set and reproduce flow rates with high precision, serving as an essential control component in analyzer systems, sampling panels, and pilot-scale process loops.
PRODUCT IMAGES



NUPRO SS-4BMG Bellows-Sealed Metering Valve
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- Authentic & Fully Tested: 100% bench tested for hydraulic response, pressure rating, and null-bias stability before dispatch.
- Fast Dispatch: In-stock units ready for same-day dispatch via DHL / FedEx Express directly to your plant.
- Pre-Shipment Verification: High-definition photos, video testing runs, and serial number verification provided prior to shipment.
- Peace of Mind: Covered by our 12-Month Replacement Warranty.
Shop the genuine NUPRO SS-4BMG Bellows Metering Valve. This USA-made high-pressure hydraulic component features a packless bellows design, delivering leak-free, reliable fluid control for heavy-duty industrial systems.