NOV Sheaves for IRI 1996-2002 & IRI-160D Workover Rigs

Product Introduction

This comprehensive IRI rig sheave kit includes direct-fit OEM replacement sheaves for crown block assemblies and traveling block assemblies (UTB-110-4-24, UTB-160-4-30 Mod F, UTB-265-5-36-11), available in standard diameters (24″, 30″, 36″) and groove widths (1″, 1-1/8″) to match exact IRI rig specifications. Unlike generic aftermarket sheaves, each component is manufactured to the exact design specs of NOV IRI workover rigs, eliminating compatibility issues, ensuring proper wire rope alignment, and maintaining safe hoisting load ratings for well workover and pulling operations.

Functional Specifications

• Crown Block Sheaves: 24″ (1″ groove), 30″ (1″ groove), 30″ (1-1/8″ groove), and 36″ (1-1/8″ groove) models support overhead wire rope guidance, distributing hoisting loads evenly across the crown block assembly for stable pipe pulling and running operations.
• Traveling Block Sheaves: 24″, 30″, and 36″ diameter models (UTB series compatible) mate with traveling block assemblies, providing smooth wire rope movement and absorbing dynamic loads during pipe hoisting and landing.
• Load & Compatibility Ratings: All sheaves are rated for IRI rig working load limits, with precision groove profiles to prevent wire rope pinching, abrasion, or slippage during high-tension workover tasks.

Structural Characteristics

All IRI rig sheaves feature rugged, workover-specific construction for maximum durability: forged/cast high-carbon steel hubs resist cracking under cyclic heavy loads; precision-machined grooves with rounded edges minimize wire rope wear; surface hardening (40–45 HRC) boosts abrasion resistance against rope friction; reinforced bearing mounts ensure stable rotation and reduce vibration. Sheaves are designed for tool-friendly field installation, with exact bolt-hole alignment and hub dimensions to fit OEM crown/traveling block assemblies without modification.

Applicable Operating Conditions

These sheaves are engineered to perform reliably in demanding workover environments, perfectly suited for:

• NOV IRI workover rigs (1996–2002 production) and IRI-160D workover rigs (1998)
• Crown block and traveling block (UTB-110, UTB-160, UTB-265) hoisting systems
• High-tension pipe pulling, running, and well workover operations
• Onshore workover sites with exposure to dust, moisture, and heavy cyclic loads
• Compliance with API 8A/8C hoisting equipment safety standards

Maintenance & Servicing Recommendations

1. Pre-Installation Verification: Cross-reference NOV part numbers against IRI rig technical manuals to confirm diameter, groove width, and assembly fitment; inspect sheaves for cracks, surface defects, or groove wear before installation.
2. Sheave Inspection Schedule: Check sheave groove wear, hub integrity, and bearing rotation every 1,000 workover hours; replace sheaves if groove depth is reduced by 10% or more, or if cracks/corrosion are present.
3. Wire Rope Compatibility: Ensure sheave groove width matches wire rope diameter (1″ groove for 1″ rope, 1-1/8″ groove for 1-1/8″ rope) to prevent premature rope or sheave failure.
4. Lubrication & Alignment: Lubricate sheave bearings per OEM specifications; verify proper sheave alignment with wire rope to avoid side loading and uneven wear.
5. Load Monitoring: Avoid overloading sheaves beyond IRI rig rated working loads; inspect sheaves for deformation after heavy hoisting events.

We supply the following spare parts:

NOV original code	NOV new code	Description	Drilling rig	U.M.
B 1254-93	B125493	Pulley B1254-93 SHEAVE 1″* 24″ or equivalent for crownblock (for IRI workover rig, 1996-2002, manufactured by NOV)	IRI, 1996-2002	pcs
111 765 05 (30″)	6094D113C	Pulley 111 756 05 (30″) or equivalent for crownblock (for IRI workover rig, 1996-2002, manufactured by NOV)	IRI, 1996-2002	pcs
3-B-1254-69 (24″)	B125469 / 10270333-001	Pulley 3-B-1254-69 24″ DIA.SHEAVE-1″ WL(STD.) or equivalent for the UTB-110-4-24 Traveling block (for IRI workover rig, 1996-2002, manufactured by NOV )	IRI, 1996-2002	pcs
4-B1254-73 (1″)	10270338-001	Pulley Sheave 4-B1254-73 1″groove* 30″ dia sheave or equivalent for Traveling block UTB-160-4-30 mod. F (for IRI	IRI, 1996-2002	pcs
		workover rig, 1996-2002, manufactured by NOV)
BMT 1254-14 (30″)	B125474 /11474664-001 (REPLACES 125414)	Pulley BMT.1254-14 30″ FABRIFORM SHEAVE-1-1/8″ or equivalent for Traveling block UTB-160-4-30 mod. F (for IRI	IRI, 1996-2002	pcs
		workover rig, 1996-2002, manufactured by NOV)
3-В1254-94 1 1/8″х36″	B125494	Pulley 3-B1254-94 1 1/8″x36″ or equivalent for crownblock (for IRI- 160D workover rig, 1998, manufacturer NOV)	IRI-160D	pcs
3-В1254-89 1 1/8″х30″	B125489	Pulley 3-B1254-89 1 1/8″x30″ or equivalent for crownblock (for IRI- 160D workover rig, 1998, manufacturer NOV)	IRI-160D	pcs
36″ ВМТ-1254-37	B125437	Pulley 36″ BMT-1254-37 or equivalent for Traveling block UTB-265-5-36-11 (for IRI-160D workover rig, 1998, manufacturer NOV)	IRI-160D	pcs

Field Fault Repair Cases for IRI Rig Sheaves

Case 1: Crown Block Sheave Groove Wear & Wire Rope Abrasion

An IRI 1999 workover rig experienced excessive wire rope abrasion and fraying, caused by worn 24″ crown block sheave grooves (B125493). The damaged sheaves risked rope failure and workover shutdown. Replacing the worn sheaves with OEM-matched B125493 models restored proper rope alignment and eliminated abrasion.

Case 2: Traveling Block Sheave Hub Crack

A UTB-160 traveling block on an IRI-160D rig developed a cracked 30″ sheave hub (B125474) during heavy pipe pulling, creating a critical hoisting safety hazard. Immediate sheave replacement was required to resume operations. Installing a new B125474 sheave restored traveling block structural integrity and safe hoisting capability.

Case 3: Misaligned Sheave Causing Rope Slippage

An IRI 2001 rig experienced wire rope slippage on the UTB-110 traveling block, traced to a worn 24″ sheave (B125469) with misaligned grooves. The slippage disrupted pipe handling and slowed workover operations. Fitting a new OEM B125469 sheave fixed rope alignment and eliminated slippage.

Frequently Asked Questions (FAQ)

Question	Answer
Are these sheaves compatible only with 1996–2002 IRI rigs and IRI-160D?	Yes, these sheaves are precision engineered exclusively for NOV IRI workover rigs (1996–2002) and IRI-160D (1998), with exact OEM part number matching for crown/traveling block fitment.
What diameter and groove widths are available for these IRI sheaves?	Sheaves are available in 24″, 30″, and 36″ diameters, with 1″ and 1-1/8″ groove widths to match crown block and UTB traveling block specifications for IRI rigs.
Do these sheaves meet API hoisting equipment standards?	Yes, all IRI rig sheaves comply with API 8A/8C standards for oilfield hoisting systems, ensuring safe performance under rated workover loads.

Procurement Guidance & Closing Statement

For workover rig maintenance teams, procurement managers, and hoisting system technicians responsible for keeping IRI 1996–2002 and IRI-160D rigs operational in high-demand oilfield workover sites, this sheave catalog provides a fully OEM-compliant, quality-assured sourcing solution for crown block and traveling block sheaves. Backed by strict API manufacturing standards and exact NOV part number matching, these sheaves eliminate compatibility risks, streamline on-rig hoisting system repairs, and provide a clear technical benchmark to resolve sheave-related faults quickly and effectively. Whether stocking for routine preventive replacement, emergency wear/crack repairs, or full crown/traveling block overhauls, these model-specific sheaves ensure adherence to global hoisting safety standards, minimize costly unplanned workover downtime, and preserve the long-term service life of your IRI rig hoisting equipment. Secure the precision-machined, load-rated sheaves your IRI workover rig needs to maintain reliable, efficient, and uninterrupted pipe pulling and well service operations.