Duckbill Valves for Qingdao Desalination Plant
Location: Qingdao China
Terms of Delivery:
Products: Duckbill Valves
Item list:
| Item | Type | Size | Qty. | Others |
| 1 | Flange | DN800 | 8 | Hand Built |
| 2 | Flange | DN1400 | 2 | Hand Built |
Project Information
1. Introduction and Objective
As an alternative to rejection of brine directly into the sea, a solution of provisionally discharging it into the river with 8 x 800mm diffuser pipes distributed over the last 40 meters of the Brine Discharge Pipe has been proposed.
To have a distributed flow among the 5 diffuser pipes and to avoid backflow of river water into the pipe during high tide, each diffuser pipe is to be fitted with a DN800 rubber duckbill check valve.
This Technical Specification is to clarify the conditions to be fulfilled by the supplier of the aforementioned duckbill check valves for the provisional river discharge diffusers.
The minimum technical requirements of valves and some basic details of construction are included in this specification; however the manufacturer is solely responsible for the design and construction of all details of the valves to be provided to ensure reliable operation, safe and appropriate application in accordance with the regulations and standards, good practices and their own experience.
2. Considerations
Header pipe: material GRP, Ø1600 mm
Discharge diffuser pipes: material GRP, Ø800 mm, PN6
Nominal flow of the Header 1600 mm pipe =1.77 m3/s
Maximum flow of the Header 1600 mm pipe = 3.03 m3/s
The nominal velocity at which the Brine passes through each diffuser pipe:
Flow through each diffuser port =1.77/5 = 0.354 m3/s Nominal Flow
Velocity at which the brine flows through each diffuser=0.856 m/s Nominal Velocity
3. Scope of Supply
The Supply scope must include the following:
Five units of duckbill check valves with retainingring flange matching the required specification.
The proper shipping and packaging toensure functional integrity.
Material Certificate for the retainingflange (Back up ring).
Technical documentation (dimensional sketches,operating conditions, installation manuals, maintenance and operationmanuals, etc.).
The supply shall not include fasteners for connection to piping or assembling of the valves in the site.
4. Codes and Standards
Valves andflanges shall be designed and manufactured with dimensions according to ANSI:American National Standards Institute.
Rest of the standardsfollowed for manufacturing shall be consistent with International Standards.
5. Materials and external appearance
The outer surfaces of the valves shall be delivered clean, free of damage and dents, finished with a natural surface and proper aesthetic.
Material of Valve – Natural Rubber
Material of retaining ring flange – Stainless Steel 316 L and flange drilling as per ANSI B 16.5 Class # 150.
6. Operating Conditions
The valve shall be designed to work in a marine environment (tidal river, salinity 35,000ppm approx.) with a service fluid of brine water (Salinity over 50,000ppm). Operating temperature range is -16.4ºC to 37.4ºC.
The design life of the valve shall be 25 years. Any parts requiring periodic replacement shall be noted by the supplier and an estimated service life given (minimum 2 years normal service).
Maximum valve submersion depth: 1.5m to centre.
The valve shall open with 35mm cracking (opening) head.
The maximum head loss at nominal flow shall be less than 7% when submerged and less than 5% when in open air.
7. Identification
Each valve shall carry its own
Factory Identification number.
Nominal sizes or diameter.
Pressure rating.
8. Performance and Mechanical Guarantee
The warranty period for mechanical characteristics and performance shall be for a period of 24 months from the date of delivery.
9. Technical data
The Technical Offer must contain the following information:
Description of each of the valves offered, including a data sheet that specifies the conditions of design, materials, dimensions and other characteristics.
Specifically, the supplier shall provide the full dimensions and required clearances, opening pressure and valve resistance coefficient, k, for both open-air and submerged operation.
Dimensional drawings and section drawings with parts description and materials.
Preliminary fabrication and quality inspection program (ITP).
10. Supplier Documentation
All documents submitted to Befesa related to this technical specification need a Befesa logo including an identification number with in the following format:
111391-GE-000-014-xxx.yy.
where the sequential number, xxx, will be used by the Provider to numbering all documents issued,
and the number of the revision, yy, will be used to control changes on documents. Revision will include number only.
Befesa provides the Supplier with the following documentation.
Title boxes for the drawings
Frontpages for Excel and docs
This documentation should be coded as it has been explained before.
Any doubt related to the coded documentation should be submitted to Befesa to solve it as soon as possible.
11. Typical Installation
