What is the most critical checklist item for screw pumps?

Viscosity range verification is most critical. Ensure pump covers full range from cold start (high viscosity) to hot operation (low viscosity). Missing this causes startup failures or poor efficiency.

How do I score vendor proposals objectively?

Use weighted scoring matrix with predefined criteria. Assign weights based on project criticality. Score each vendor 0-5 against each criterion and calculate weighted totals. Document all scores with justification.

What documentation must vendors provide?

Required: completed datasheet, performance curves at specified viscosity, deviation list, GA and sectional drawings, material list, reference list, and delivery schedule. Missing documents should trigger clarification request.

Screw Pump Vendor Proposal Review Checklist

1. Technical Compliance Checklist

General Requirements

Item	Yes	No	N/A
Vendor on Approved Vendor List (AVL)	□	□	□
Pump type matches specification	□	□	□
API 676 compliance confirmed	□	□	□
Deviations clearly listed	□	□	□
All datasheet fields completed	□	□	□

Process Requirements

Item	Specified	Offered	Acceptable
Rated flow (m³/h)			□ Yes □ No
Differential pressure (bar)			□ Yes □ No
Operating temperature (°C)			□ Yes □ No
Design pressure (barg)			□ Yes □ No
Operating viscosity (cSt)			□ Yes □ No
Cold start viscosity (cSt)			□ Yes □ No

Mechanical Requirements

Item	Yes	No	Notes
Relief valve included	□	□	CRITICAL
Relief valve set pressure correct	□	□	≤110% operating
Nozzle sizes correct	□	□
Flange ratings correct	□	□
Baseplate design adequate	□	□
Drain and vent provided	□	□

2. Performance Verification

Flow and Efficiency

Item	Yes	No	Notes
Performance curves provided	□	□
Curves at specified viscosity	□	□	CRITICAL
Rated point marked on curves	□	□
Flow tolerance stated (±3%)	□	□
Slip percentage specified	□	□
Volumetric efficiency stated	□	□

Operating Point Analysis

Parameter	Value	Within Range?
Flow at rated speed	___	□ Yes □ No
Slip at operating viscosity	%	□ <10% OK
Volumetric efficiency	%	□ >85% OK
Overall efficiency	%	□ >70% OK
Power at duty point	kW	□ Within motor

Viscosity Coverage

Condition	Viscosity	Covered?
Cold start (min °C)	___ cSt	□ Yes □ No
Normal operation	___ cSt	□ Yes □ No
Hot operation (max °C)	___ cSt	□ Yes □ No

3. Displacement and Speed

Displacement Verification

Item	Specified	Offered	Notes
Displacement (cc/rev)
Rated speed (RPM)
Speed range (if VFD)
Theoretical flow (L/min)

Speed Considerations

Check	Yes	No
Speed appropriate for viscosity	□	□
VFD required and included	□	□
Minimum speed stated	□	□
Maximum speed stated	□	□

4. Material Verification

Wetted Parts

Component	Required	Offered	Compatible
Casing			□ Yes □ No
Rotors/Screws			□ Yes □ No
Shaft			□ Yes □ No
Bearings			□ Yes □ No
Wear components			□ Yes □ No
O-rings/seals			□ Yes □ No

Special Requirements

Requirement	Required	Confirmed
NACE MR0175 compliance	□ Yes □ N/A	□
Low temperature rating	□ Yes □ N/A	□
Food grade (FDA)	□ Yes □ N/A	□
Material test reports (MTR)	□ Yes □ N/A	□

5. Bearing and Seal Review

Bearing Design

Item	Specified	Acceptable
Bearing type		□ Yes □ No
L10 life (hours)	>15,000	□ Yes □ No
Lubrication type		□ Yes □ No

Seal Design

Item	Specified	Offered	Acceptable
Seal type			□ Yes □ No
API 682 arrangement			□ Yes □ No
Flush plan			□ Yes □ No
Seal materials			□ Yes □ No

6. Protection Systems

Mandatory Items

Item	Required	Included
Relief valve	MANDATORY	□ Yes □ No
Relief valve set pressure	≤110%	___ barg
Relief valve capacity	Full flow	□ Yes □ No
Pressure gauge	□	□ Yes □ No

Optional Protection

Item	Specified	Included
Suction strainer	□ Yes □ No	□
Pressure transmitter	□ Yes □ No	□
Temperature sensor	□ Yes □ No	□
Vibration monitor	□ Yes □ No	□

7. Documentation Completeness

With Proposal

Document	Provided	Complete
Completed datasheet	□	□
Deviation list	□	□
Performance curves	□	□
GA drawing	□	□
Sectional drawing	□	□
Material list	□	□
Reference list (min 3)	□	□
Delivery schedule	□	□
Spare parts list	□	□

Drawing Review

Item	Yes	No
Overall dimensions acceptable	□	□
Nozzle locations correct	□	□
Foundation loads provided	□	□
Maintenance clearances adequate	□	□

8. Commercial Terms

Warranty

Item	Required	Offered	Acceptable
Warranty period	months	months	□ Yes □ No
Warranty start			□ Yes □ No

Delivery

Item	Required	Offered	Acceptable
Delivery time (weeks)			□ Yes □ No
Delivery terms			□ Yes □ No

Spare Parts

List	Provided	Priced
Commissioning spares	□	□
2-year operating spares	□	□
Lead times	□	□

9. Exception Handling

Deviation Classification

Classification	Definition	Action
Critical	Affects safety or performance	Resolve before award
Major	Significant impact	Negotiate resolution
Minor	Limited impact	Accept with documentation

Deviation Tracking

#	Class	Decision
1	□ C □ M □ Mi	□ Accept □ Reject □ Clarify
2	□ C □ M □ Mi	□ Accept □ Reject □ Clarify
3	□ C □ M □ Mi	□ Accept □ Reject □ Clarify

10. Scoring Template

Weighted Evaluation Matrix

Category	Weight	Score (0-5)	Weighted
Technical compliance	35%
Performance verification	20%
Materials	15%
Vendor experience	10%
Documentation quality	10%
Commercial terms	10%
TOTAL	100%

Scoring Rubric

Score	Description
5	Exceeds requirements, no deviations
4	Meets all requirements
3	Minor deviations, acceptable
2	Significant deviations, needs work
1	Major gaps
0	Does not comply

Quick Reference: Must-Check Items

Non-Negotiable Requirements

Relief valve included
Viscosity range covers cold start to hot operation
Performance curves at specified viscosity
L10 bearing life ≥ 15,000 hours
Slip specified and acceptable (<10%)
Materials compatible with fluid
API 676 compliance (if specified)

Automatic Rejection Criteria

No relief valve
Cannot handle specified viscosity range
No performance curves provided
L10 life below minimum
Materials incompatible with process
No valid references
Incomplete mandatory documentation

Screw Pump Vendor Proposal Review Checklist

1. Technical Compliance Checklist

General Requirements

Process Requirements

Mechanical Requirements

2. Performance Verification

Flow and Efficiency

Operating Point Analysis

Viscosity Coverage

3. Displacement and Speed

Displacement Verification

Speed Considerations

4. Material Verification

Wetted Parts

Special Requirements

5. Bearing and Seal Review

Bearing Design

Seal Design

6. Protection Systems

Mandatory Items

Optional Protection

7. Documentation Completeness

With Proposal

Drawing Review

8. Commercial Terms

Warranty

Delivery

Spare Parts

9. Exception Handling

Deviation Classification

Deviation Tracking

10. Scoring Template

Weighted Evaluation Matrix

Scoring Rubric

Quick Reference: Must-Check Items

Non-Negotiable Requirements

Automatic Rejection Criteria

❓Frequently Asked Questions

📚References & Sources

Need Help Evaluating Vendor Proposals?

1. Technical Compliance Checklist

General Requirements

Process Requirements

Mechanical Requirements

2. Performance Verification

Flow and Efficiency

Operating Point Analysis

Viscosity Coverage

3. Displacement and Speed

Displacement Verification

Speed Considerations

4. Material Verification

Wetted Parts

Special Requirements

5. Bearing and Seal Review

Bearing Design

Seal Design

6. Protection Systems

Mandatory Items

Optional Protection

7. Documentation Completeness

With Proposal

Drawing Review

8. Commercial Terms

Warranty

Delivery

Spare Parts

9. Exception Handling

Deviation Classification

Deviation Tracking

10. Scoring Template

Weighted Evaluation Matrix

Scoring Rubric

Quick Reference: Must-Check Items

Non-Negotiable Requirements

Automatic Rejection Criteria

❓Frequently Asked Questions

📚References & Sources

🔗Related Articles

Need Help Evaluating Vendor Proposals?