Z45X Rubber Resilient Seated Gate Valve
• Flanged resilient-seated gate valve with full NBR rubber coating for zero-leakage water sealing
• Dual pressure ratings: PN10 and PN16, DN50–DN600 size range
• HT200 ductile cast iron body with full internal/external epoxy coating
• NBR rubber encapsulated disc and seat for excellent wear and corrosion resistance
• Working temperature up to 80°C for municipal water, HVAC, and irrigation systems
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Product Details
The Z45X rubber resilient seated gate valve is a flanged, non-rising stem (NRS) gate valve built for water supply, distribution and transmission. Its wedge is fully encapsulated in nitrile-butadiene rubber (NBR) and the body cavity is lined as well, so the valve shuts bubble-tight even when the water carries sand, silt and suspended solids that would defeat a metal seat. The ductile cast iron (HT200) body carries a full internal and external epoxy coating for buried or submerged service. The series covers DN50–DN600 in two pressure classes, PN10 and PN16, with a working temperature to 80°C.
- Fully NBR-encapsulated wedge and lined body cavity — bubble-tight zero-leakage shut-off on dirty water
- Internal and external epoxy coating on the ductile cast iron (HT200) body for buried, submerged service
- Non-rising stem (NRS): compact installed height for vaults, chambers and tight spaces
- Two pressure classes, PN10 (Z45X-10) and PN16 (Z45X-16), across DN50–DN600
- 2Cr13 stainless steel stem and NBR gaskets — low-maintenance water-service trim
- Rated for water and non-corrosive fluids to 80°C: waterworks, fire systems, irrigation, HVAC
Product Overview
The Z45X is a resilient-seated gate valve for potable and industrial water networks. Both the body cavity and the disc are lined with NBR, which makes the sealing surface elastic: on closing, the rubber wedge deforms slightly and absorbs or crushes fine sediment carried in the main rather than being gouged by it. That is the core reason this pattern — rather than a metal-seated gate — is specified on municipal water, where a line is never truly clean and “no leakage” is a contractual requirement on isolation.
The body and bonnet are ductile cast iron marked HT200, coated inside and out with epoxy, on a 2Cr13 stainless steel stem with NBR gaskets, so the valve tolerates long-term burial and submerged chamber service without the corrosion that seizes bare-iron gates. Non-rising stem construction keeps the installed height constant, which is what makes the valve fit under chamber covers and below ground.
Be clear about what it is not. The NBR lining fixes the ceiling at 80°C: for hotter water, steam or any gas service, this is the wrong valve. It is an isolation device — hold it fully open or fully closed, never throttling, or the flowing stream cuts the rubber. And where the specification prefers a lappable metal seat, the Z45T bronze seat gate valve is the same NRS pattern with a different sealing philosophy.
What the Model Code Means
Z = gate valve, 4 = flanged connection, 5 = non-rising stem wedge gate, X = resilient (rubber) seat — the elastomer lining that gives the pattern its name; the suffix -10 / -16 is the PN10 / PN16 class. Designation follows the GB valve coding method (JB/T 308); decode any model digit by digit on the Valve Model Decoder.
Core Strengths
Fully Coated NBR Rubber Seat
Entire body interior coated with NBR rubber lining provides bubble-tight zero-leakage sealing against waterborne sediment, sand, and particulate matter.
Epoxy Coating Corrosion Protection
Full epoxy coating on both internal and external surfaces delivers superior corrosion resistance for water service, extending service life in aggressive water environments.
Non-Rising Stem Design
Compact non-rising stem (NRS) construction minimizes installation height — ideal for underground vaults, valve chambers, and space-constrained applications.
Dual Pressure Rating Options
Available in both PN10 and PN16 pressure classes across DN50–DN600, covering municipal mains through industrial water distribution networks.
Stainless Stem, Sealed Bonnet Cavity
The stem is 2Cr13 stainless steel and the bonnet joints seal with NBR gaskets, so the load-bearing and weeper-prone parts of the valve sit inside a coated, elastomer-sealed body that is designed to stay where it was buried for decades without the external corrosion that seizes bare-iron gate valves.
A Seat That Absorbs Grit Instead of Fighting It
Because the sealing faces are elastic NBR bonded over the whole wedge, fine solids in the water are embedded or compressed by the rubber on closure rather than scratching a machined metal seat. The page’s own maintenance rule still stands — exercise idle valves monthly so the rubber does not bond to the disc where it sits.
Performance Specifications
| Model | Nominal Pressure PN (MPa) | Shell Test Pressure (MPa) | Seal Test Pressure (MPa) | Working Temperature (°C) | Applicable Medium |
|---|---|---|---|---|---|
| Z45X-10 | 1.0 | 1.5 | 1.1 | ≤80 | Water |
| Z45X-16 | 1.6 | 2.4 | 1.8 | ≤80 | Water |
Z45X-10 is rated PN10 (1.0 MPa), shell tested at 1.5 MPa and seat tested at 1.1 MPa; Z45X-16 is PN16 (1.6 MPa), shell 2.4 MPa, seat 1.8 MPa. Both classes share the same working limit: water and non-corrosive fluids to 80°C. The ceiling belongs to the NBR lining — do not buy temperature margin into this pattern.
Main Component Materials
| NO | Part Name | Material |
|---|---|---|
| 1 | Valve Body, Bonnet | Ductile Cast Iron (HT200), Epoxy Coated |
| 2 | Seal Ring (Seat) | Full Epoxy Coat (Entire Cavity Lining) |
| 3 | Disc (Gate/Wedge) | HT200 Cast Iron + NBR Rubber Encapsulation |
| 4 | Valve Stem | 2Cr13 Stainless Steel |
| 5 | Gasket / Pad | NBR Rubber (Nitrile Butadiene Rubber) |
Valve body and bonnet: ductile cast iron marked HT200, epoxy coated. Disc: HT200 cast iron with NBR rubber encapsulation. Seat ring: full epoxy cavity lining. Stem: 2Cr13 stainless steel. Gasket/pad: NBR rubber.
Main Dimensions — Manual Flanged PN10/PN16 (mm)
DN50 – DN150
| Nominal size | L (face-to-face) | H (total height) | D0 (handwheel dia.) |
|---|---|---|---|
| DN50 | 178 | 270 | 180 |
| DN65 | 190 | 300 | 180 |
| DN80 | 203 | 320 | 240 |
| DN100 | 229 | 350 | 240 |
| DN125 | 254 | 400 | 280 |
| DN150 | 267 | 455 | 280 |
DN200 – DN400
| Nominal size | L (face-to-face) | H (total height) | D0 (handwheel dia.) |
|---|---|---|---|
| DN200 | 292 | 560 | 320 |
| DN250 | 330 | 650 | 360 |
| DN300 | 356 | 770 | 400 |
| DN350 | 381 | 870 | 500 |
| DN400 | 406 | 1010 | 640 |
DN450 – DN600
| Nominal size | L (face-to-face) | H (total height) | D0 (handwheel dia.) |
|---|---|---|---|
| DN450 | 432 | 1080 | 640 |
| DN500 | 457 | 1180 | 640 |
| DN600 | 508 | 1345 | 640 |
L = face-to-face length, H = total height, D0 = handwheel diameter, all in millimetres. The dimensions apply to both the PN10 and PN16 classes, as stated on the page. No weight figures are published for this series; lifting data comes with the quotation, and certified dimensional drawings are issued with every offer.
Rubber Seat, Bronze Seat or Plate Gate: Choosing the Right Isolation Valve
| Requirement | Z45X resilient seated (NBR) | Z45T bronze seat | RZ47F/RZ43F plate gate |
|---|---|---|---|
| Shut-off on dirty water | Bubble-tight; rubber absorbs sand and solids | Metal seat tolerates grit; may weep at zero flow | Not a water pattern — gas-service seat |
| Drinking water hygiene / corrosion | Lined cavity + full epoxy coat, no bare iron wetted | Uncoated iron body, bronze seat rings | Cast steel body for hydrocarbon service |
| Temperature ceiling | 80°C (set by NBR) | 135°C (metal seat) | −29–121°C (gas media) |
| Buried vaults and fire-water mains | Default choice: NRS, coated, zero-leakage | Where loose shut-off is accepted, cheaper | No — for gas pipelines only |
| Pressure classes | PN10 / PN16 | PN10 | PN10–PN40 |
Pick the Z45X when zero leakage on water is the contract requirement and the duty stays at or below 80°C. Choose the Z45T bronze seat gate where a lappable metal seat, hotter water or 135°C duty is specified. Never stretch either pattern to gas — that is what the RZ47F/RZ43F gas plate gate valve exists for.
Structure Drawing
Design & Manufacturing Standards
- Design and manufacture: GB/T 12232
- Testing and inspection: GB/T 13927, API 598, ISO 5208
- Flange reference: ANSI B16.5
- Valve designation: JB/T 308
These are the standards listed for the series on the product page. If your tender names other waterworks specifications, send the document with your enquiry so we can confirm what this pattern is actually tested to before you commit.
Installation & Maintenance Guidelines
- Orientation: Install vertically or horizontally as required by pipeline orientation. Ensure adequate clearance for handwheel operation and maintenance access.
- Flush first: Flush the pipeline thoroughly before installation to prevent debris from damaging the NBR rubber-coated seal surfaces during initial commissioning.
- Never lift by the handwheel: Do not use the handwheel as a lifting point — excessive force can damage the bonnet assembly, stem threads, and NBR rubber seals.
- Exercise idle valves: For valves installed but idle over extended periods, operate the handwheel periodically (monthly recommended) to prevent the NBR rubber seat from bonding to the disc surface.
- Check the gaskets: Inspect NBR gaskets during routine maintenance. Replace if signs of hardening, cracking, or permanent compression set are observed.
- Full open or full closed: The rubber seat and the wedge are not built to survive a throttling stream; part-open operation erodes the lining.
- Cycle before burial: On non-rising stems, position is not visible — record the number of turns to full open and verify the stroke before the chamber is backfilled.
Application Fields
The Z45X is the isolation valve of choice wherever water must be stopped dead and the valve may be buried or forgotten: municipal water supply and distribution networks; fire protection systems including hydrant lines and sprinkler mains; agricultural irrigation systems; HVAC chilled-water and hot-water circuits; process water treatment plants and cooling towers; and general industrial fluid isolation on water and non-corrosive fluids. The fire-protection and buried-vault duties are where the NRS, coated, zero-leakage combination earns its place — a rising stem simply does not fit under a chamber cover.
What We Need to Quote Your Z45X Gate Valves
- Size and class: DN50–DN600, PN10 (Z45X-10) or PN16 (Z45X-16); mixed schedules welcome.
- Medium and temperature: water and non-corrosive fluids; confirm anything above 80°C is out of scope before we quote.
- Service duty: buried chamber, fire main or pump station — it decides packing length and whether an extension stem is needed.
- Stem and headwork: NRS as standard; state if you need a position indicator, key head or extension spindle.
- Mating flanges: the series lists ANSI B16.5; tell us your flange standard so bolting matches the site.
- Accessories: spares, gaskets, gland sets for the maintenance store.
- Documentation: test records against the listed inspection standards for tender packages.
Send the valve schedule and we will return class-by-class dimensions, weights and a priced offer. Drawings are in the download center and factory qualifications on the certifications page.
Frequently Asked Questions
How is a resilient seated gate valve different from a bronze seat gate valve?
The sealing element. A Z45X wedge is fully encapsulated in NBR, so the seat is elastic, absorbs grit carried in the water and gives bubble-tight shut-off – but the rubber caps service at 80 degC. A Z45T has machined bronze seat rings: a metal seat that tolerates up to 135 degC and can be lapped in the field, at the cost of a slightly less perfect shut-off on dirty water. Both are the same non-rising stem flanged pattern.
Can the Z45X be used on a gas or compressed air line?
No. The published medium for this series is water and non-corrosive fluids; an NBR lined seat tested on water is not a gas seal, and gas exposes leakage that water does not. For gas service use the RZ47F/RZ43F gas plate gate valve from the same gate valve family.
Why is the temperature limited to 80°C when the iron body can take much more?
Because the sealing element fails long before the casting does. NBR softens, hardens and takes permanent compression set with heat cycling; at 80 degC the rubber still returns after each stroke. Above that, the seat is the weak link regardless of the ductile iron body, so specify a metal-seated pattern instead.
Non-rising stem – how do my operators know if it is open or shut?
They cannot read it from the stem, which is the accepted trade-off for the compact installed height. Count turns to full open at commissioning, record them on the tag line, and specify a handwheel position indicator if the valve sits in a vault that different crews visit.
Should we stock PN10 or PN16?
Both share DN50-DN600 and the same dimensions; PN16 (Z45X-16) has the higher pressure and test ratings, so many water authorities standardise on PN16 for mains and use PN10 where the design head is modest. Tell us the pump shut-off head and the network design pressure and we will confirm the class per duty.
The valve has sat closed for three years. Will it open?
Usually yes, with patience – the coating and stainless stem are the point of the design. The published maintenance advice is to exercise the valve monthly to stop the NBR seat bonding to the disc; on a neglected valve, back the handwheel off gently rather than forcing it, and expect to repack or re-gasket if the bonnet shows weepage.
Gaoshan Valve has manufactured industrial valves since 1975 and holds ISO 9001/14001/45001 with CE, API 6D and PED product certification. It is an approved supplier to Sinopec, CNPC and State Grid and exports to more than 30 countries, supplying water utilities, power plants and EPC contractors.
Get a Quote & Technical Support
Contact Gaoshan Valve for Z45X dimension sheets, coating details, stem extension options and a class-by-class selection for your water network. Reply within 1 business day from our overseas sales desk; CAD drawings, test certificates and OEM customization available.
