What is the most important criteria when evaluating mag-drive pump quotations?

Protection systems (power monitor, dry-run protection) are most critical. A mag-drive pump without proper protection will fail within seconds of a dry-run event. Always verify these are included in the scope of supply.

How should I weight the evaluation criteria?

Typical weighting: Technical Compliance 40-50%, Materials 15-20%, Vendor Experience 10-15%, Delivery 10-15%, Lifecycle Cost 10-15%, Documentation 5-10%. Adjust based on project criticality.

What are red flags in mag-drive pump quotations?

Major red flags include: no power monitor, no dry-run protection, inadequate magnetic torque margin, pump not rated for specified temperature, claiming solids handling capability, and significantly lower price without clear explanation.

How to Evaluate Magnetic Drive Pump Vendor Quotations

TBE Evaluation Categories

Weighted Scoring Matrix

Category	Weight	Key Evaluation Points
Technical Compliance	40-50%	Hydraulic performance, magnetic coupling, protection
Materials of Construction	15-20%	Chemical compatibility, corrosion resistance
Vendor Experience	10-15%	References, manufacturing history, service
Delivery Schedule	10-15%	Project schedule alignment
Lifecycle Cost	10-15%	Energy, maintenance, spare parts
Documentation Quality	5-10%	Completeness, clarity, compliance

Technical Compliance Evaluation

Hydraulic Performance

Parameter	What to Verify	Acceptance Criteria
Rated Flow	Meets duty point	Within ±2% of specified
Rated Head	At rated flow	Within ±2% of specified
Efficiency	Compare at BEP and rated	-5% tolerance
NPSHr	Below NPSHa	NPSHa - NPSHr ≥ 0.5m
Operating Range	Covers all conditions	70-120% of BEP minimum

Critical Check: Request performance curves and verify duty point falls within preferred operating region (80-110% of BEP).

Magnetic Coupling Design

Parameter	What to Verify	Why It Matters
Magnetic Loss	kW at duty point	Motor sizing, energy cost
Coupling Torque	Rating vs required	Decoupling prevention
Service Factor	Per API 685	Safety margin
Magnet Material	NdFeB vs SmCo	Temperature capability
Max Temperature	vs process + eddy heat	Demagnetization prevention

Protection Systems (Critical)

Protection	Status	Notes
Power Monitor	MANDATORY	Detect dry-run, decoupling
Temperature Sensor	MANDATORY	Bearing/shell protection
Dry-Run Protection	MANDATORY	Flow switch or under-current
Minimum Flow Device	As Required	Orifice or ARC valve

Reject if: Power monitor or dry-run protection not included

Materials Evaluation

Wetted Components Checklist

Component	Verify Against	Common Issues
Casing	Process chemical	Chloride attack on SS
Impeller	Corrosion + erosion	Material mismatch
Containment Shell	Temp + chemical	Wrong grade Hastelloy
Bearings	Fluid compatibility	pH extremes
Magnet Encapsulation	Chemical + temp	Inadequate protection

Material Deviation Analysis

Deviation	Risk Level	Action
Alternative equivalent alloy	Medium	Request corrosion data
Different bearing material	High	Verify with fluid
Metallic vs non-metallic shell	Medium	Check efficiency impact
Different magnet encapsulation	High	Verify compatibility

Scoring Methodology

Scoring Scale

Score	Definition	Criteria
5	Excellent	Fully compliant + exceeds requirements
4	Good	Fully compliant with all requirements
3	Acceptable	Minor deviations, acceptable with clarification
2	Marginal	Significant deviations, needs major clarification
1	Unacceptable	Does not meet minimum requirements
0	Non-compliant	Missing or completely non-responsive

Sample Evaluation Matrix

Criteria	Weight	Vendor A	Vendor B	Vendor C
Hydraulic Performance	20%	4	5	3
Magnetic Coupling Design	15%	4	4	4
Materials Compatibility	15%	5	4	4
Protection Systems	10%	3	5	4
Vendor Experience	10%	5	4	3
References	5%	5	3	2
Delivery	10%	4	4	5
Lifecycle Cost	10%	3	4	4
Documentation	5%	4	4	3
Weighted Score	100%	4.05	4.25	3.60

Common Deviations

Hydraulic Deviations

Deviation	Risk	Evaluation Guidance
Oversized impeller	Medium	Check efficiency at duty point
Lower NPSHr margin	High	Verify ≥0.5m margin remains
Flat curve near shutoff	High	Not suitable for parallel operation
Different speed	Medium	Verify motor compatibility

Material Deviations

Deviation	Risk	Evaluation Guidance
Alternative alloy	Medium-High	Request corrosion data
Different bearing material	High	Verify with process fluid
Metallic vs non-metallic shell	Medium	Check efficiency impact

Design Deviations

Deviation	Risk	Action
No power monitor	Critical	REJECT
No dry-run protection	Critical	REJECT
Lower magnetic torque rating	High	Risk of decoupling
Different coupling configuration	Medium	Verify performance

Red Flags in Vendor Proposals

Critical Red Flags (Potential Rejection)

Red Flag	Why It Matters
No power monitor included	Undetected dry-run = magnet damage
Inadequate magnetic torque margin	Decoupling during transients
Missing dry-run protection	Bearing failure in seconds
Pump not rated for specified temp	Demagnetization risk
No eddy current loss data	Cannot verify motor sizing
Claiming solids handling	Mag-drive cannot handle solids

Warning Signs (Require Clarification)

Warning Sign	Questions to Ask
Significantly lower price	What is excluded from scope?
Very short delivery	Is this proven design or new?
Limited reference list	Request extended warranty
Incomplete data sheets	Request full completion
Vague deviation descriptions	Request detailed clarification

Lifecycle Cost Analysis

Cost Components (15-20 Year Life)

Component	% of LCC	Notes for Mag-Drive
Initial Purchase	10%	Higher than sealed pumps
Energy	40%	Include magnetic losses
Maintenance	25%	Lower - no seal maintenance
Operations	15%	Similar to sealed pumps
Downtime	5%	Lower - better MTBF
Disposal	5%	Similar to sealed

Comparison: Mag-Drive vs Sealed Pump

Factor	Sealed Pump	Mag-Drive
Initial Cost	Lower	20-40% higher
Energy Cost	Lower	10-15% higher
Seal Maintenance	$500-5,000/year	$0
MTBF	2-5 years	8-10+ years
Environmental Cost	Potential leaks	Zero emissions
Total 10-year Cost	Baseline	Often 10-20% lower

Energy Cost Calculation

Annual Energy Cost = (Power × Hours × Rate) / Efficiency

Example:
- Motor power: 15 kW
- Operating hours: 8,000 hr/year
- Energy rate: $0.10/kWh
- Include eddy losses: +2 kW

Annual cost = (17 × 8000 × 0.10) = $13,600/year

Performance Guarantees

Required Guarantees (per API 685)

Parameter	Tolerance	Verification
Flow at rated point	±2%	Factory test
Head at rated point	±2%	Factory test
Efficiency	-5%	Factory test
NPSHr	-0% / +10%	Factory test
Power	+4%	Factory test

Additional Guarantees to Request

Guarantee	Typical Terms
Mechanical Warranty	18-24 months from shipment
Performance Warranty	Same as mechanical
MTBF Guarantee	5-8 years minimum
Spare Parts Availability	10-15 years
Magnet Life	10+ years at rated conditions

Vendor Experience Requirements

Reference Requirements

Criterion	Minimum	Preferred
Number of References	3	5+
Similar Fluid Type	Same family	Identical fluid
Operating Pressure	Within 20%	Same or higher
Operating Temperature	Within 20%	Same or higher
Operating Duration	1 year	3+ years

Questions for References

How long has the pump been in operation?
What has been the MTBF?
Have there been bearing or magnet failures?
What was vendor response to warranty claims?
Would you purchase from this vendor again?
Any operating limitations discovered?
Quality of documentation?
Spare parts availability?

Documentation Requirements

With Quotation

For Final Documentation

Phase	Documents
Kickoff	Quality Plan, Schedule, Sub-vendor list
Manufacturing	Material Certs, NDT Reports, Progress
Testing	Test Procedures, Reports, Certificates
Shipment	Final Drawings, O&M Manual, Databook

TBE Process Summary

1. RECEIVE BIDS
   ↓
2. INITIAL SCREENING (completeness, deviations)
   ↓
3. TECHNICAL EVALUATION (score against criteria)
   ↓
4. ISSUE TECHNICAL CLARIFICATION (TCL)
   ↓
5. RECEIVE CLARIFICATIONS
   ↓
6. UPDATED EVALUATION (re-score)
   ↓
7. LIFECYCLE COST ANALYSIS
   ↓
8. PREPARE TBE REPORT
   ↓
9. SUBMIT FOR APPROVAL
   ↓
10. TECHNICAL AWARD RECOMMENDATION

Key Takeaways

Must-Verify Items

Power monitor - mandatory protection
Magnetic torque rating - adequate margin
Bearing material - appropriate for fluid
Containment shell - compatible material
NPSHr margin - minimum 0.5m below NPSHa

Must-Request Items

Magnetic loss data at duty point
Complete deviation list
Verified reference list
API 685 compliant data sheets
Lifecycle cost estimate

Must-Reject Conditions

No dry-run protection provided
No power monitor in scope
Inadequate magnetic torque
Pump not rated for temperature
No proven references