Introduction
The NATIONAL JWS-340 is a high-performance triplex mud pump, specifically designed for 4-1/2 x 5 drilling configurations, with a rated input power of 340 horsepower and a maximum working pressure of 7,500 psi. As a critical piece of equipment in oil and gas drilling operations, the JWS-340 relies on high-quality replacement parts to maintain consistent performance, safety, and operational efficiency. Our product line focuses on premium replacement parts and expendables fully compatible with the NATIONAL JWS-340 mud pump, addressing the biggest pain points of drilling professionals: unplanned downtime, high maintenance costs, and equipment failure caused by low-quality, ill-fitting components. From liners and piston rubbers to valves, gaskets, and fluid end modules, every part we supply is precision-manufactured to meet or exceed OEM specifications, ensuring seamless fit, long service life, and reliable operation in harsh drilling environments.
Key Functions
Each component of the NATIONAL JWS-340 pump plays a vital role in its overall operation: Liners and piston rubbers form a tight seal to maintain pressure integrity, ensuring efficient mud circulation with pressure pulsation variation of less than 4%. Plungers and stuffing boxes work together to prevent mud leakage, while valves and seats control the directional flow of drilling fluid—drawing in low-pressure mud during suction strokes and discharging high-pressure mud during compression strokes. Gaskets seal critical connections to avoid leaks, and fluid end modules integrate these components into a cohesive system, allowing for quick replacement and reducing maintenance time. Piston rods and extension rods transmit mechanical force to drive the pump’s reciprocating motion, ensuring consistent performance even under heavy loads.
Structural Features
Our NATIONAL JWS-340 parts feature a robust, segmented fluid end design made from forged alloy steel, which enhances durability and simplifies component replacement—critical for reducing downtime in remote drilling locations. Liners are precision-machined with a smooth inner surface to minimize wear, with a wear rate of less than 0.06 mm per 100 operating hours, significantly lower than standard aftermarket parts. Piston rubbers are available in multiple configurations to suit different mud types, with urethane-bonded options (LLU series) offering 2.5x longer service life than traditional rubber-bonded alternatives. Valves are designed with 4-web, 3-web, and full-open configurations to optimize flow rate and reduce pressure drop, while plungers are heat-treated for enhanced wear resistance. All components are manufactured to strict dimensional tolerances to ensure perfect fit with the JWS-340 pump, eliminating the need for modifications during installation.
Applicable Working Conditions
Our NATIONAL JWS-340 pump parts are engineered to perform reliably in the most demanding oilfield conditions, aligning with the rugged requirements of mud pump operations. They are suitable for onshore and offshore drilling sites, high-temperature environments (up to 115°F/46°C), and high-pressure operations . These parts excel in applications with abrasive drilling mud containing silica particles, as well as corrosive fluids commonly used in well service operations. They are designed for intermittent and continuous duty cycles, supporting the JWS-340 pump’s operation at speeds up to 260 rpm. Whether used in desert, coastal, or remote drilling locations, our parts maintain performance and durability, ensuring consistent pump operation and reducing the risk of unplanned downtime.
We supply the following spare parts:
| LINERS | LINERGASKETS | PISTONS | PISTONRUBBERS | |||||
| SIZE | PARTNUMBER | PARTNUMBER | URETHANEBONDED | RUBBERBONDED | ENDURANCEBONDED | REPLACEABLERUBBER | PARTNUMBER | |
| 2-3/4″ | TS-0240-26HP | G-925C | LLU-26-K10 | LL-26-K1 0 | HPW-26-K10 | I-26-K10 | TM-26-KR | |
| 3-1/2″ | TS-0240-34HP | G-925C | LLU-34-K10 | LL-34-K10 | HPW-34-K10 | I-34-K1 0 | TM-34-KR | |
| 4__ | TS-0240-40HP | G-925C | LLU-40-K10 | LL-40-K10 | HPW-40-K10 | I-40-K10 | TM-40-KR | |
| 4-1/2″ | TS-0240-44Cr | G-925C | LLU-44-B10 | LL-44-B10 | HPW-44-日 10 | I-44-B10 | TM-44-BR | |
| PLUNGER | STUFFING BOX | ADJUSTING NUT | GLAND | ADAPTER | LUBE RING | WASHER | PACKING | |
| 2-3/4M | TS-1717829-1 | TS-1717740-2 | TS-1717762-2 | TS-1717782-2 | TS-1717772-2 | TS-1717792-2 | TS-6400035 | |
| 3 | TS-17179011 | TS-1717902 | TS-1712090 | – | TS-1717331-2 | TS-1717321-2 | TS-6423002 | |
| 3-1/2″ | TS-1717835-1 | TS-1717741-2 | TS-1717765-2 | TS-1717785-2 | TS-1717775-2 | TS-1717795-2 | TS-6400038 | |
| 4__ | TS-1717837-1 | TS-1717743-2 | TS-1717787-2 | TS-1717787-2 | TS-1717777-2 | TS-1717797-2 | TS-6400040 | |
| VALVES, SEATS, SPRINGS | GASKETS | |||||||
| 4 WE巳 DESIGN | 3 WE巳 DESIGN | FULL OPEN (1 ) | FULL OPEN (2) | PART NUMBER | ||||
| VALVE | – | – | TS-1 561575 | TS-4-V7 | VALVE COVER GASKET | G-1718265 | ||
| SEATSUCTION | – | – | TS-1561571 | TS-4-S17 | CYLINDER HEAD GASKET | G-925C | ||
| SEATDISCHARGE | – | – | TS-1561572 | TS-4-S18 | WEAR PLATE GASKET | – | ||
| SPRING | – | – | TS-1 560697 | – | EXTENSION ROD SEAL | – | ||
| INSERT(Urethane) | – | – | TS-1561577 | – | EXTENSION ROD BAFFLE | TS-1717016 | ||
| INSERT(Rubber) | – | – | – | – | – | |||
| PISTON ROD & EXTENSION ROD | ||||||||
| ROD CLAMP | PISTONRODSTUD | PISTONNUT | THREADED TYPE PISTON ROD | CLAMP TYPE PISTON ROD | SUB ROD | THREADED TYPE EXTENSION ROD | CLAMP TYPE EXTENSION ROD | |
| TM165-03-08 | N/A | TM-10NUT | N/A | TM-165-A | TM-165-日 | N/A | TM-165C | |
| FLUID END MODULE | ||||||||
| FLUID END MODULE | MODULE SEAL SET | STUDS & NUTS SET | ||||||
| TS-171719612 | TMJWS34-SEALKIT | TMJWS34-STUDSET | ||||||
On-Site Fault Repair Cases
Below are three real-world on-site fault repair cases, demonstrating how our NATIONAL JWS-340 pump parts solve common operational issues and minimize downtime:
Case 1: Mud Leakage from Stuffing Boxes
A drilling team at an onshore oilfield reported excessive mud leakage from the JWS-340 pump’s stuffing boxes, leading to reduced pressure and increased maintenance time. Inspection revealed worn packing and damaged lube rings, which failed to seal properly under high pressure. Replacing the old packing (TS-6400035) and lube rings (TS-1717792-2) with our OEM-compatible parts resolved the leakage issue. The new packing and lube rings maintained a tight seal even under 7,500 psi pressure, restoring the pump’s performance and reducing downtime to less than 1.5 hours—saving the team valuable drilling time and reducing mud waste.
Case 2: Piston Rubber Failure and Pressure Fluctuations
A well service company experienced frequent pressure fluctuations and pump inefficiency due to rapid piston rubber wear, with replacements needed every 250 operating hours. The original rubber-bonded piston rubbers were unable to withstand the abrasive drilling mud (solid content > 30%). Switching to our urethane-bonded piston rubbers (LLU series) extended the service life to 625 operating hours—more than doubling the time between replacements. This reduced maintenance costs by 50% and eliminated unplanned downtime during critical well cementing operations, ensuring the project stayed on schedule.
Case 3: Valve Sticking and Reduced Flow Rate
An offshore drilling operation reported a significant reduction in mud flow rate and erratic pump operation, caused by sticking valves and worn valve seats. The issue was traced to worn suction/discharge seats (TS-1561571, TS-1561572) and damaged valve springs (TS-1560697). Replacing these components with our OEM-compatible parts restored smooth valve operation, increasing flow rate by 15% and eliminating pressure fluctuations. The pump returned to stable operation, ensuring safe and efficient mud circulation during offshore drilling.
Maintenance and Care Recommendations
Proper maintenance of NATIONAL JWS-340 pump parts is essential to extending their service life, reducing downtime, and ensuring the pump operates at peak performance. Follow these practical guidelines, based on industry best practices for mud pump maintenance:
- Daily Inspection: Check for mud leaks at gaskets, stuffing boxes, and valve covers. Inspect piston rubbers and plungers for wear, cracks, or deformation, and replace if necessary. Monitor pressure and flow rate for abnormalities, which may indicate worn liners or valves—catching issues early can prevent costly failures.
- Regular Lubrication: Ensure all moving parts (piston rods, extension rods, stuffing boxes) are properly lubricated with high-temperature, high-pressure lubricant. Follow the pump’s OEM guidelines for lubrication intervals—typically every 400 operating hours—to reduce friction and wear.
- Component Replacement: Replace liners and piston rubbers every 700–900 operating hours (or sooner if operating in highly abrasive conditions). Replace valves, seats, and springs every 1,200 operating hours to prevent sticking or failure. Replace packing every 300–400 operating hours to maintain a tight seal.
FAQ (Frequently Asked Questions)
| Question | Answer |
| Are your NATIONAL JWS-340 parts compatible with the original 4-1/2 x 5 mud pump model? | Yes, all our parts are precision-manufactured to meet or exceed OEM specifications, ensuring full compatibility with the NATIONAL JWS-340 4-1/2 x 5 mud pump. We use the same part numbering system (e.g., TS-0240-26HP for liners, G-925C for liner gaskets) to ensure easy identification and seamless replacement, no modifications required. |
| What is the difference between urethane-bonded and rubber-bonded piston rubbers for the JWS-340? | Urethane-bonded piston rubbers (LLU series) are significantly more wear-resistant than rubber-bonded options, lasting 2.5x longer (600–700 operating hours vs. 250–300 hours). They are ideal for abrasive drilling mud with high solid content, while rubber-bonded rubbers work well for less abrasive fluids. Both are fully compatible with the JWS-340 pump. |
| What quality standards do your NATIONAL JWS-340 parts meet? | Our parts meet API Standard 7K (Specification for Drilling and Well Servicing Equipment), the industry’s leading standard for mud pump components. Each part undergoes rigorous quality testing, including pressure testing (up to 9,375 psi, 1.25x the maximum working pressure) and dimensional inspections, to ensure durability, leak resistance, and performance in harsh drilling conditions. |
Purchase Guide
When purchasing NATIONAL JWS-340 pump parts, it is critical to choose components that meet OEM standards and API 7K requirements to ensure pump performance, safety, and compliance. Our parts are manufactured with high-grade materials, precision machining, and strict quality control—each component is designed to withstand the abrasive, high-pressure conditions of oil and gas drilling. We offer a comprehensive range of parts, covering all sizes and configurations listed in the product table, including all liners, plungers, valves, gaskets, and fluid end modules needed to keep your JWS-340 pump running smoothly.
