Flow Optimizer Grated Insert
PUMP SUCTION ELBOW RETROFIT
Evaluate a grated insert for your existing elbow
A Flow Optimizer grated insert uses a vane grid to condition flow in piping. For a suitable existing clean-water suction elbow, an insert may be positioned at the downstream end with the grid extending upstream into the bend. This arrangement is evaluated around the actual pump and piping.
Clean-water suitability and suction head belong together
Check head loss and NPSH before installation
The elbow-retrofit arrangement discussed here is for clean-water applications. Review the potential for debris or blockage and the head loss introduced by the grid.
Added suction-side pressure loss can reduce net positive suction head available (NPSHA). Confirm that the pump’s required NPSH margin is maintained across the intended operating range. Where margin is limited, additional loss can increase the risk of cavitation.
Head-loss information: Flow Optimizers does not currently have head-loss data or calculations for this grated elbow retrofit. Determine the proposed insert’s pressure loss and its effect on NPSH for the actual design and operating range.
Technical reference: ANSI/HI 9.6.6-2022 — Rotodynamic Pumps for Pump Piping. Review the proposed flow-conditioning arrangement against the actual pump, piping and project requirements.
Review the proposed geometry
Confirm grid depth, passages, flange arrangement and the relationship to the elbow outlet and pump suction.
Review the complete flow path
Location and orientation should be established during application review. A project drawing is needed before treating an arrangement as an installation instruction.
See the side-by-side vaned elbow and grated insert comparison →
Review the installation before selecting the grid
- Approach flow: Identify the disturbance the insert is intended to address.
- Fit and connections: Confirm elbow dimensions, flange details and internal clearances.
- Operating range: Evaluate performance and added pressure loss across the intended flow range.
- Liquid and debris: Confirm clean-water suitability and potential blockage risks for the elbow-retrofit arrangement.
- Access: Consider installation, inspection and maintenance requirements.
Other flow-conditioning applications
Grated inserts may also be evaluated for other piping and measurement applications. Those installations require their own review of the liquid, upstream geometry, placement and applicable equipment requirements.
Engineering, Design and Fabrication for Flow Conditioning
The linked reference specification describes a grid-insert arrangement. It does not establish verified head-loss performance for the grated elbow retrofit. Confirm dimensions, material, placement and hydraulic requirements for the actual application.
Conveniently flange mounted onto pipes, elbows, and Tee’s.
Flanged Flow Straightening Grid Insert for Pipe
- Purpose: Flow straightening insert with vaned flow conditioning to straighten flow.
- Documentation: Provide a certified drawing for review with pump submittal.
- Design Criteria:
- Minimum Length: Three times the grid length.
- Grid Spacing: Varies based on diameter and maximum flow rate, maintaining 7 feet/second or less.
- Head Loss Coefficient (K): Not established for the grated elbow retrofit. Determine an appropriate value for the actual geometry and operating flow before evaluating suction losses.
- Construction:
- Material: 316L stainless steel.
- Thickness: Determined by the design engineer.
- Flange: Bolt hole drilling pattern to ASME B16.5 Class 150.
Download Specifications:
Flow Conditioning Grated Inserts
Flow Conditioning Grated Insert Drawings
Flow Conditioning Grated Insert Project Gallery
Contact Us
Contact us for more information or for help with your specific application.
Could either approach fit your pump installation?
Send the information you have so Flow Optimizers can review the application with you:
- Pump manufacturer, model and suction size
- Design flow rate and expected operating range
- Elbow size, radius, dimensions and flange details
- A photo or drawing showing the elbow and surrounding suction piping
- Liquid handled, debris or solids concerns and installation access
- Available NPSH information and the operating concern, if known
The team can identify any additional information needed before recommending a configuration.
Questions about elbow flow conditioning
Is a vaned elbow always the best option?
Selection depends on the full suction arrangement, available space, liquid handled and operating range. Review the installation before choosing an elbow, insert or other approach.
Can I add a grated insert to an existing elbow?
A retrofit may be possible in a suitable clean-water installation. The review should confirm internal dimensions, connections, access, location and orientation, grid head loss and required NPSH margin.
Will flow conditioning solve every pump problem?
Flow conditioning addresses the approach-flow condition. Noise, vibration and performance problems can also have mechanical or other hydraulic causes, so the responsible engineering team should evaluate the complete system.