Non-rising Resilient Seat Gate Valve

Non-rising Resilient Seat Gate Valve Purpose                                                 

This valve is mounted on various pipelines and used as a bi-way closed circuit equipment for tap water,  sewage treatment, metallurgy, petroleum, building, chemical, electric

industries etc.

Non-rising Resilient Seat Gate Valve Definition and Components

1.1 What is a Z45X Non-rising Resilient Seat Gate Valve?

Z45X is a standardized Chinese designation for a specific type of gate valve:

Z: Gate Valve

4: Connection Type - Flanged

5: Structure Type - Non-rising Stem

X: Seat Material - Resilient (Rubber) Seat

This is a non-rising stem, flanged, resilient-seated gate valve that features a fully encapsulated rubber-coated gate and an internal stem mechanism where the stem does not move upward when operated. Instead, the gate rises internally while the handwheel and stem nut move vertically within the valve body.

1.2Non-rising Resilient Seat Gate Valve Main Components

Component	Material/Type	Critical Function	Special Features
1. Valve Body	Ductile Iron (QT450-10), Cast Iron (HT250), Cast Steel (WCB)	Main pressure-retaining component with flow passage	Compact design, integral flanges
2. Resilient Gate	Cast Iron/Steel core +Full Rubber Encapsulation(EPDM/NBR)	Primary sealing element with elastic surface	Bubble-tight sealing, corrosion-resistant coating
3. Non-rising Stem	Stainless Steel (2Cr13, 304SS)	Transmits rotational motion to linear gate movement	Threads inside valve body, stem position fixed
4. Stem Nut (Yoke Bush)	Bronze/Copper Alloy or Stainless Steel	Converts rotary to linear motion	Self-lubricating, wear-resistant
5. Body Seat Rings	Ductile Iron/Stainless Steel with machined surfaces	Provides sealing surface for rubber gate	Replaceable in some designs
6. Stem Seal/Packing	PTFE/V-ring packing or O-ring seals	Prevents leakage along stem	Adjustable packing gland
7. Handwheel/Operator	Cast iron with epoxy coating	Manual operation interface	Fixed position, ergonomic design
8. Bonnet/Yoke Assembly	Same as body material	Encloses stem mechanism	Bolted or pressure-sealed design

 Role, Characteristics, and Application Scenarios of Non-rising Resilient Seat Gate Valve in Pipelines

2.1 Pipeline Functions

Full Flow Isolation: Provides straight-through flow with minimal pressure drop when open

Bubble-tight Shutoff: Achieves zero-leakage closure in both directions

Space-efficient Operation: Non-rising stem design saves vertical space

Low Maintenance: Resilient seat requires no lubrication or adjustment

Corrosion Protection: Rubber encapsulation protects metal components from corrosive media

2.2 Operational Features

Feature	Technical Explanation	Operational Benefit
Non-rising Stem	Stem rotates but doesn't ascend; gate rises internally	Space-saving - no overhead clearance needed
Resilient Sealing	Rubber-to-metal sealing interface	Bubble-tight closure without metal-to-metal contact
Low Operating Torque	Rubber compression vs metal friction	Easy manual operation even in large sizes
Bi-directional Flow	Symmetrical gate and seat design	Installation independent of flow direction
Full Bore Design	Gate retracts completely into bonnet	Minimal pressure loss when open
Maintenance-free Seat	Rubber doesn't require lubrication or adjustment	Reduced lifecycle costs

2.3 Water Valves Application Scenario Diagram

Typical Application Industries:

Industry	Specific Application	Why Z45X is Suitable
Water Supply & Distribution	Main line isolation, branch connections	Bubble-tight seal for potable water, no contamination
Wastewater Treatment	Effluent lines, sludge handling	Corrosion resistance to sewage, easy operation
Building Services	Basement mechanical rooms, pipe chases	Space-saving design in confined areas
Irrigation Systems	Main line control, zone valves	Reliable sealing, minimal pressure loss
Industrial Water	Cooling water, process water lines	Low maintenance, durable in continuous service
HVAC Systems	Chilled/heating water isolation	Excellent sealing, compact installation

 

Non-rising Resilient Seat Gate Valve Standards: Materials, Design, and Connections

1 Gate Valve for Water Material Standards

Component	Standard	Common Materials
Body & Bonnet	ASTM A126 Class B, ASTM A216 WCB	Gray Cast Iron, Ductile Iron QT450-10
Gate	ASTM A48, with rubber encapsulation	Cast Iron + EPDM/NBR/Viton
Stem	ASTM A276, ASTM A564	304SS, 316SS, 17-4PH
Stem Nut	ASTM B584, ASTM B505	C83600 Bronze, C93200 Bronze
Seat Rings	ASTM A126, ASTM A216	Cast Iron, Ductile Iron, Stainless Steel
Bolting	ASTM A193, ASTM A307	B7, B8, Grade 5
Rubber Components	FDA 21 CFR 177, WRAS, NSF/ANSI 61	EPDM, NBR, Viton

3.2 Design Standards

Standard	Title	Key Requirements
API 600	Steel Gate Valves	Design basis for bolted bonnet valves
API 603	Corrosion-resistant Gate Valves	For severe service applications
ISO 5208	Industrial Valves Pressure Testing	Leakage rate classifications
MSS SP-70	Cast Iron Gate Valves	Design requirements for iron body valves
MSS SP-80	Bronze Gate Valves	Construction standards
BS EN 1171	Industrial Valves - Cast Iron Gate Valves	European standard
AWWA C509	Resilient-seated Gate Valves for Water Supply	Water industry standard

3.3 Connection Standards

Flange Standard	Pressure Classes	Face Type	Common Applications
ASME B16.1	Class 125, 250	Raised Face	Cast Iron flanges (US)
EN 1092-2	PN10, PN16, PN25	Type A, B1, B2	Cast Iron flanges (EU)
ASME B16.5	Class 150	Raised Face	Steel flanges
JIS B2220	5K, 10K	Raised Face	Japanese standard
ISO 7005-2	PN10-PN25	Raised Face	International projects

Face-to-Face Dimensions: Generally comply with ISO 5752 or API 600 Annex A

How to Select Non-rising Resilient Seat Gate Valve

4.1 Technical Specification Development

4.2 Critical Specification Elements

1. Service Conditions (Must Specify):

Fluid type and characteristics (pH, chlorine content, solids)

Operating pressure and test pressure requirements

Temperature range (minimum, normal, maximum)

Cycling requirements (operations per year)

External environment (buried, submerged, corrosive atmosphere)

1. Design Requirements:

Pressure class: PN10, PN16, Class 125, Class 150

End connection type and standard

Face-to-face dimensions

Stem orientation (vertical/horizontal operation)

By-pass requirement (for large diameters)

Position indicator requirement

1. Material Selection Guide:

Service Condition	Body Material	Gate Coating	Stem Material
Potable Water	Ductile Iron QT450-10	EPDM (NSF 61)	304SS
Wastewater	Gray Cast Iron	NBR or EPDM	316SS
Sea Water	Bronze or 316SS	EPDM	316SS or Monel
Industrial Water	Ductile Iron or WCB	EPDM or Viton	304SS or 17-4PH

1. Special Requirements:

Fire-safe design: Generally NOT available for resilient-seated valves

Cryogenic service: Not recommended (rubber becomes brittle)

Abrasive media: Not recommended (rubber wears quickly)

Steam service: Not suitable (temperature too high)

4.3 Supplier Evaluation Factors

 

Evaluation Category	Weight	Key Assessment Criteria
Technical Compliance	30%	Meets all specifications, proper certifications
Quality Management	25%	ISO 9001 certified, testing procedures, quality records
Manufacturing Capability	20%	Production capacity, equipment, technical expertise
Delivery Performance	15%	On-time delivery history, lead time commitments
Cost Competitiveness	10%	Price, payment terms, total cost of ownership

Certification Requirements:

ISO 9001 Quality Management System

NSF/ANSI 61 for potable water applications

CE Marking for European market

Local approvals (WRAS, UL, FM as required)

4.4 Purchase Documentation

Ensure the purchase order includes:

Complete technical specification sheet

Reference to all applicable standards

Inspection and test requirements (ITP)

Documentation deliverables list

Packaging and marking requirements

Spare parts requirements

Warranty terms and conditions

Pre-Shipment Inspection for Export Non-rising Resilient Seat Gate Valve and Key Considerations

5.1 Comprehensive Inspection Protocol

Phase 1: Documentation Review

REQUIRED DOCUMENTS CHECKLIST:

✓ Material Certificates (EN 10204 3.1 for metallic parts)

✓ Rubber Material Certificates (with FDA/NSF if applicable)

✓ Pressure Test Certificates

✓ Dimensional Inspection Reports

✓ Certificate of Conformity

✓ Operation & Maintenance Manuals

✓ Packing List

Phase 2: Visual and Dimensional Inspection

Inspection Area	Check Points	Acceptance Criteria
External Surface	Casting quality, finish, defects	No cracks, porosity, or defects affecting integrity
Flange Faces	Surface finish, scratches, gouges	Smooth, no damage affecting sealing
Markings	Identification per MSS SP-25	Legible, permanent, complete information
Dimensions	Face-to-face, flange dimensions	Within tolerance per specified standards
Coating	Paint thickness, adhesion, coverage	Per specification, minimum 200渭m DFT

 

Phase 3: Material Verification

Positive Material Identification (PMI): Verify alloy composition of stem

Hardness Testing: Check body and critical components

Rubber Testing: Verify durometer hardness (if test samples available)

Phase 4: Pressure Testing (Per API 598/ISO 5208)

SHELL TEST (High Pressure):

• Test Pressure: 1.5 × PN rating
• Medium: Water
• Duration: Minimum per standard (based on size)
• Acceptance: No visible leakage, no permanent deformation

SEAT TEST (Low Pressure):

• Test Pressure: 1.1 × PN rating
• Medium: Air (preferred for bubble detection) or water
• Duration: Minimum per standard
• Acceptance: Zero visible leakage for resilient seats

TEST SEQUENCE:

1. Partially open valve (10% open)
2. Fill body with test medium
3. Apply shell test pressure
4. Close valve against pressure
5. Release body pressure
6. Apply seat test pressure upstream
7. Check downstream for leakage
8. Repeat for opposite direction

Phase 5: Functional Testing

Operation Test: 3 complete open-close cycles minimum

Torque Measurement: Record maximum operating torque

Stem Seal Test: Check for leakage along stem during/after operation

Position Verification: Ensure full open and full closed positions are achievable

5.2 Special Considerations for Resilient-Seated Gate Valves

1. Gate Inspection:

Verify complete rubber encapsulation with no voids or defects

Check for uniform rubber thickness (typically 3-6mm)

Ensure rubber is firmly bonded to metal core

Verify gate edges are properly protected by rubber

1. Seat Contact Verification:

Visual inspection of seat surfaces for smooth finish

Check for uniform contact pattern (after pressure test)

Verify no metal-to-metal contact points

1. Stem/Stem Nut Engagement:

Check thread engagement throughout full travel

Verify smooth operation without binding

Ensure adequate lubrication on threads (if specified)

5.3 Export Preparation Protocol

1. Cleaning and Preservation:

Complete Internal Cleaning: Remove all test water and debris

Drying: Compressed air blow-down to remove moisture

Rust Prevention: Apply VCI (Vapor Corrosion Inhibitor) to internal surfaces

External Protection: Touch-up paint on any damaged coating

Desiccant Placement: For valves > DN200, place desiccant bags inside

1. Protective Packaging:

Individual Valve Protection:

Flange Face Protection: 3mm minimum thickness plastic/metal covers bolted in place

Stem Protection: Plastic cap over stem end

Handwheel Protection: Cardboard or foam wrapping

Gate Position: Secure in fully open position to prevent rubber compression set

Internal Protection:

VCI emitter placed inside valve body

Moisture indicator visible through open end

Warning tag: "Remove desiccant before installation"

Crating Requirements (for sea freight):

Wooden Crates: ISPM-15 compliant (heat treated or fumigated)

Internal Blocking: Prevent movement during transit

Weather Protection: Polyethylene lining or waterproof paper

Lifting Points: Clearly marked with safe working load

1. Marking and Labeling:

Crate Marking (All sides):

CONSIGNEE: [Name/Address]

SHIP TO: [Site/Project]

VALVE ID: [Tag Number]

PACKAGE: [X of Y]

GROSS WEIGHT: [kg]

NET WEIGHT: [kg]

DIMENSIONS: [L×W×H]

HANDLE WITH CARE

KEEP DRY

THIS SIDE UP

Valve Body Marking (Per MSS SP-25):

Manufacturer's name or trademark

Pressure class designation (PN or Class)

Material designation

Size (DN and NPS)

Directional flow arrow (if applicable)

Heat number (for steel valves)

1. Documentation Package:

Shipping Documents:

Commercial Invoice (3 copies)

Packing List (detailed per crate)

Bill of Lading / Air Waybill

Certificate of Origin

Insurance Certificate

Export Declaration

Technical Documents (Waterproof envelope inside crate):

Test and Inspection Reports:

Material Test Certificates

Pressure Test Certificates

Final Inspection Report

Certificates:

Certificate of Conformity

NSF/ANSI 61 Certificate (if applicable)

CE Declaration of Conformity (if applicable)

User Documentation:

Installation Instructions

Operation and Maintenance Manual

Spare Parts List

Warranty Certificate

5.4 Special Precautions for Resilient-Seated Valves

1. Temperature Considerations:

Store in temperature-controlled environment if possible

Avoid exposure to direct sunlight for extended periods

Temperature range during storage: -10°C to +40°C

1. Rubber Protection:

Protect from ozone, oils, and solvents

Avoid compression of rubber gate during storage

Ensure rubber components are not in contact with VCI materials that may degrade rubber

1. Long-term Storage:

For storage >6 months, partially exercise valve quarterly

Check desiccant condition monthly

Maintain proper ventilation in storage area

5.5 Final Inspection Checklist

Before Crate Closure:

All protective covers in place and secured

Valve secured in fully open position

Desiccant and moisture indicator placed

VCI emitter activated (if used)

Internal inspection completed and documented

All accessories included (bolts, gaskets if specified)

Before Shipment Release:

All test certificates verified and included

Documentation package complete

Markings clear and correct

Weight and dimensions recorded

Crating secure and weatherproof

Shipping documents prepared

Insurance arranged

5.6 Common Issues to Prevent

Potential Issue	Preventive Action	Detection Method
Rubber Degradation	Proper storage conditions, UV protection	Visual inspection, hardness test
Seat Compression Set	Store valve in open position	Gate movement check, torque measurement
Corrosion	Complete drying, VCI application	Internal inspection, moisture indicator
Shipping Damage	Adequate blocking and bracing	Crate inspection, shock indicator
Documentation Errors	Cross-check against packing list	Document review before sealing

Non-rising Resilient Seat Gate ValveMain dimensions(mm)

DN		50	65	80	100	125	150	200	250	300	350	400	450	500	600	700	800
L	GB	178	190	203	229	254	267	292	330	356	381	406	432	457	508	605	665
	DIN	150	170	180	190	200	210	230	250	270	290	310	330	350	390	430	470
H		233	255	275	330	370	432	495	589	670	1050	1170	1270	1420	1650	1900	2100
D0		180	180	230	230	280	280	330	380	380	380	480	480	600	600	800	800

Note:1. Other specifications and flange standards are available upon request.

2. Design and specifications are subject to change without prior notice.