Flanged Resilient Seated NRS Gate Valve
Flanged Resilient Seated NRS Gate Valve Definition and Components
A Flanged Resilient Seated NRS Gate Valve Model No.Z45X-03 is an industrial Ductile Iron ul/fm Flanged NRS Gate Valve with flanged connections,a resilient(rubber)seat for tight sealing,and a Non-Rising Stem(NRS).The model number"Z45X-03"is a manufacturer's code where Z=Gate Valve,45=Flanged,X=Resilient Seated,03=Design Variant(often indicating a specific pressure class or feature set).
Main Parts:
- Valve Body:Main pressure-containing housing with integral flanges.
- Bonnet:Bolted cover that houses the stem assembly.
- Gate/Disc:The moving part that blocks flow,typically with a full rubber encapsulation.
- Resilient Seat:An elastomeric(e.g.,EPDM,NBR)ring against which the gate seals.
- Stem(Non-Rising):A threaded shaft that moves the gate up/down without itself rising.
- Stem Nut&Handwheel:Mechanism to turn the stem.
- Packing Box:Seals around the stem to prevent leakage.
- Flanges:Machined faces for bolting to pipeline flanges.
Role, Characteristics, and Application Scenarios of Flanged Resilient Seated NRS Gate Valve in Pipelines
Fire Valve Functions:
- On/Off Isolation:Provides complete shut-off in pipelines.
- Bidirectional Sealing:Effective seal against pressure from either flow direction.
- Full Bore Flow:Minimal flow restriction when fully open.
Operational Features:
- Bubble-Tight Seal:Elastic seat ensures zero leakage.
- Compact Design:NRS saves vertical installation space.
- Low Operating Torque:Easy to open/close.
- Corrosion Resistant:Often coated internally/externally.
- Maintenance-Free:No lubrication required for the seat.
Typical Applications:
- Potable Water Distribution
- Wastewater&Sewage Treatment Plants
- Fire Protection Systems
- Industrial Cooling Water Lines
- General Service in Chemical&Process Industries
Scenario Diagram:
Flanged Resilient Seated NRS Gate Valve Standards: Materials, Design, and Connections
Fire gate valve Material Standards:
- Body/Bonnet/Gate:Ductile Iron(e.g.,ASTM A536 Gr.65-45-12/EN-GJS-500-7).
- Stem:Stainless Steel(e.g.,AISI 304,316,431).
- Seat/Seals:EPDM(for water),NBR(for oils),Viton®(FKM for chemicals).
- Bolting:Carbon Steel,Grade 8.8 or equivalent.
- Coatings:Internal epoxy(e.g.,AWWA C550),external paint or epoxy.
Design Standards:
- General:API 600,ISO 5208,MSS SP-70/80.
- Waterworks:AWWA C509/C515(common for N.America).
- Testing:API 598,ISO 5208(shell test 1.5x rating,seat test 1.1x rating).
- Face-to-Face:ANSI B16.10,EN 558-1,ISO 5752.
Connection Standards:
- Flange Standards:ANSI B16.5(Class 150/300),EN 1092-2(PN10/16/25),AS 2129.
- Flange Faces:Raised Face(RF),Flat Face(FF),or RTJ.Model Z45X-03 often has RF.
- Drilling:Matches chosen flange standard(e.g.,ANSI drilling for Class 150).
How to Select Such Flanged Resilient Seated NRS Gate Valve
Define Specifications:
- Size(DN/NPS)and Pressure Rating(PN/Class).
- Material Grades for body,stem,seat.
- Connection Details:Exact flange standard,facing,drilling.
- Operational:Manual handwheel,gear operator,or actuator requirements.
- Standards Compliance:Specify required design standards(e.g.,"to API 600").
Supplier Identification:
- Source from established valve manufacturers or authorized distributors.
- Verify quality certifications(ISO 9001).
Request Quotation(RFQ):
- Provide a clear technical data sheet.
- Request compliance certificates,material test reports,and drawings.
Evaluation&Order:
- Compare technical compliance,lead time,and commercial terms.
- Issue a Purchase Order referencing all specifications.
Documentation Review:
- Approve manufacturing drawings and test procedures from the supplier.
Pre-Shipment Inspection for Export Flanged Resilient Seated NRS Gate Valveand Key Considerations
Inspection Protocol:
Documentation Review: Verify Material Test Reports, Certificate of Compliance, and test procedures.
Visual & Dimensional Check:
No surface defects.
Flange dimensions (thickness, O.D., bolt circle, hole size) per standard.
Face-to-face length correct.
Permanent marking present (size, pressure, material, brand).
Pressure Testing (Witnessed):
- Shell Test: Typically at 1.5 x rated pressure. No leakage permitted.
- Seat Leakage Test: Typically at 1.1 x rated pressure in both directions. Allowable leakage is "zero" for resilient seated valves.
- Operational Check: Handwheel turns smoothly, gate moves fully open/closed.
Export Precautions:
Packaging:
- Flange faces MUST be protected with sturdy, bolt-on plastic/metal covers.
- Internal cavity should be dry, with Vapor Corrosion Inhibitor (VCI) bags.
- Valves securely crated on wooden pallets/skids.
Documentation for Customs:
- Accurate Packing List and Commercial Invoice.
- Ensure all certificates (MTRs, test reports) are original or certified copies ready for the consignee.