Product Overview
The Double Flapper Check Valve is a dedicated safety protection valve matched for coiled tubing downhole service, normally connected to coiled tubing connectors to provide critical anti-backflow safety guarantee. When the coiled tubing string or ground surface equipment suffers damage or failure, this double flapper check valve will automatically close to completely block reverse flow of downhole well fluid into the coiled tubing, avoiding secondary safety accidents caused by fluid backflow.
This valve adopts innovative dual flapper two-stage independent sealing structure, equipped with two separate flapper sealing cartridges. The flapper cartridges support fast disassembly, on-site replacement and maintenance without complex auxiliary tools, greatly improving field operation efficiency. It is widely applicable to all conventional coiled tubing downhole intervention treatments. Two complete service grades are supplied to match diverse reservoir environments: STD standard grade for conventional sweet oil wells without hydrogen sulfide corrosive media, and H2S sour service grade manufactured with sulfur-resistant alloy for high-H2S corrosive sour gas well working conditions.
The standardized product lineup covers outer diameter sizes ranging from 1-1/2" to 3-1/8", with matched inner diameter and make-up length specifications, equipped with standard AMMT and PAC bottom connection threads for universal compatibility with mainstream coiled tubing connectors and downhole service tools. Custom inner bore sizes, wall thickness and anti-sulfur passivation coatings are available upon customer technical drawing submission.
Complete Technical Specification Table
| PN Part Number | Outer Diameter OD | Inner Diameter ID | Make-Up Length | Working Condition Grade | Bottom Connection Thread |
|---|---|---|---|---|---|
| L1151500120 | 1-1/2" | 0.57" | 11.4" | STD Standard | 1" AMMT |
| L1151690120 | 1-11/16" | 0.7" | 11.4" | STD Standard | 1" AMMT |
| L1151750120 | 1-3/4" | 0.7" | 11.4" | STD Standard | 1" AMMT |
| L1152125120 | 2-1/8" | 0.9" | 12.5" | STD Standard | 1-1/2" AMMT |
| L1152875120 | 2-7/8" | 1.23" | 15" | STD Standard | 2-3/8" PAC |
| L1153125120 | 3-1/8" | 1.37" | 15.6" | STD Standard | 2-3/8" PAC |
| L1151500320 | 1-1/2" | 0.57" | 11.4" | H2S Sour Service | 1" AMMT |
| L1151690320 | 1-11/16" | 0.7" | 11.4" | H2S Sour Service | 1" AMMT |
| L1151750320 | 1-3/4" | 0.7" | 11.4" | H2S Sour Service | 1" AMMT |
| L1152125320 | 2-1/8" | 0.9" | 12.5" | H2S Sour Service | 1-1/2" AMMT |
| L1152875320 | 2-7/8" | 1.23" | 15" | H2S Sour Service | 2-3/8" PAC |
| L1153125320 | 3-1/8" | 1.37" | 15.6" | H2S Sour Service | 2-3/8" PAC |
Core Features & Advantages
Dual flapper two-stage series sealing structure, double independent sealing barriers greatly enhance sealing reliability, effectively eliminating well fluid leakage risk under high downhole pressure
Metal-to-metal hard sealing design for both flapper cartridges, stable zero-leakage sealing performance under long-term high-pressure and variable temperature wellbore environment, outstanding erosion and corrosion resistance
Two independent detachable flapper sealing cartridges, support quick disassembly, inspection and field replacement, reduce equipment downtime and maintenance cost
Dual service grade design: STD standard version for conventional sweet oilfield working conditions, H2S sulfur-resistant alloy version for highly corrosive high-H2S sour gas well service
Complete outer diameter series compatible with 1-1/2", 1-11/16", 1-3/4", 2-1/8", 2-7/8" and 3-1/8" coiled tubing matching assemblies, covering all mainstream small and medium-size coiled tubing heavy-load downhole service demands
Simple external threaded connection design, convenient for fast disassembly and assembly with various coiled tubing connectors on site
Precision CNC machined high-strength alloy steel valve body, excellent abrasion, erosion and pressure fatigue resistance to extend continuous long-term downhole safety service cycle
Customizable outer diameter, inner bore flow size, bottom thread specification and anti-sulfur surface passivation coatings to satisfy unique proprietary coiled tubing safety protection requirements
Application Scenarios
1. All types of coiled tubing sand washing, well cleaning, gas lifting, perforating and other downhole intervention treatments
2. Conventional sweet crude oil well coiled tubing intervention safety protection service (STD standard service grade)
3. High-H2S sour gas well corrosive environment coiled tubing string and surface equipment anti-backflow protection operations (H2S sour service grade)
4. Downhole ball dropping, plug launching and other through-tubing intervention construction requiring reliable double-stage sealing protection
5. Long-term safety protection for coiled tubing strings and ground surface equipment in onshore and offshore oilfields
Standard Delivery Package
Complete double flapper check valve main body with two independent metal-to-metal flapper sealing cartridges
Matching dual metal sealing spare parts kit for field maintenance and replacement
Full factory inspection test report including pressure resistance, dual-stage sealing leakage and flapper closing response test data
Product dimension drawing and official installation, disassembly & operation instruction manual
Quality Warranty & After-Sales Service
Warranty Coverage: 12 months after factory shipment or 2000 cumulative working hours, whichever condition is reached first.
Full factory inspection: Each finished double flapper check valve passes pressure resistance, dual-stage sealing leakage and flapper closing performance testing before delivery.
Free professional technical support: Our oilfield downhole tool engineering team provides connector matching, flapper cartridge disassembly guidance and parameter consultation free of charge.
Long-term spare parts supply: All metal sealing wear parts and flapper cartridge accessories are stocked with competitive factory bulk pricing.
Custom development service: Support custom bottom thread profiles, anti-corrosion coatings and special size double flapper check valves based on customer technical drawings.
FAQ
Q1: What is the core function of a Double Flapper Check Valve?
A1: The Double Flapper Check Valve is a coiled tubing safety valve connected to coiled tubing connectors. It adopts two independent flapper sealing cartridges to form dual-stage sealing, automatically closing to block well fluid backflow into coiled tubing when tubing string or surface equipment fails, protecting downhole and ground equipment.
Q2: What unique structural advantage does this double flapper valve own?
A2: It is equipped with two separate flapper sealing elements to realize dual-stage series sealing for higher sealing reliability; meanwhile, both flapper cartridges support quick disassembly and field replacement to simplify on-site maintenance.
Q3: What range of outer diameter sizes do these double flapper check valves support?
A3: Our standard production lineup fully covers 1-1/2", 1-11/16", 1-3/4", 2-1/8", 2-7/8" and 3-1/8" outer diameter specifications, compatible with global mainstream small and medium-size coiled tubing matching assemblies.
Q4: What is the difference between STD standard grade and H2S sour service grade?
A4: STD standard grade is manufactured for conventional sweet oil wells without hydrogen sulfide corrosive fluid. H2S sour service grade adopts sulfur-resistant alloy substrate and special anti-sulfur passivation coating to resist chemical corrosion in high-H2S sour gas well environments.
Q5: What is the standard production lead time for bulk purchase orders?
A5: All standard PN part numbers are kept in factory inventory, goods can be delivered within 7-15 working days. Customized double flapper check valves with special anti-sulfur coatings or custom flow bore dimensions require 20-35 working days production cycle, subject to total order quantity.
Get Custom Datasheet & Factory Quote
We are a professional OEM & ODM manufacturer focused on full series coiled tubing downhole service tools, covering double flapper dual-stage sealing safety valves, big ID single flapper check valves, grapple dimple composite connectors, grub screw heavy-duty connectors, double dimple-on connectors, single dimple-on connectors, double roll-on connectors, single roll-on connectors, internal grapple connectors, external grapple connectors, logging heads and tubing hangers. Every finished product undergoes strict factory pressure resistance, dual-stage sealing and flapper closing testing, with complete material inspection certification attached to each shipment. Please share your detailed technical requirements, including target outer diameter size, working environment (STD standard or H2S sour service) and customized specification demands. Our dedicated oilfield downhole tool engineering team will send complete detailed technical datasheets and competitive factory wholesale quotations within 24 business hours.
