The goal of spare parts management is simple: have commonly used parts readily available, know where to obtain large parts, and ensure inventory does not tie up funds. There is a straightforward and executable approach to determining what to stock, how much to stock, and how to manage it. By following this approach, most sites can straighten out their spare parts issues. Spare parts may not seem important at ordinary times, but only when there is a malfunction do we realize whether the accounts are clear, whether the inventory is complete, and whether the downtime is just a few hours.
Which items are worth keeping in stock
There are two criteria for judgment: whether the failure rate is high or not, and whether the impact of downtime is significant or not. Based on these two criteria, the commonly used spare parts list usually includes: seals and gaskets, which are prone to aging and must be replaced during maintenance, accounting for the majority of spare parts usage; filter elements and filter cartridges, which are replaced based on pressure difference or on a regular basis; belts and bearings, which are wear parts and will cause the device to stop directly if they fail; contactors, relays, and commonly used sensors, which are electrical wear parts with low unit prices but significant impact; commonly used valve components and specialized tools. Random accessories and specialized tools are counted and recorded upon delivery, managed in the same warehouse as spare parts, and can be easily found and matched when needed.
How much is appropriate to prepare
The reserve quantity is calculated based on the consumption rate plus the replenishment cycle: for consumable parts such as seals, prepare one quarter's worth; for filter elements, prepare one to two spare units based on the replacement cycle; for electrical wear parts, prepare one to two each. Large items such as compressors and fans should not be held in inventory - they consume funds and may deteriorate if stored for long periods. However, it is necessary to agree with the manufacturer on a supply cycle and emergency scheduling plan, and include the response time limit in the contract. The amount of inventory should not be fixed once and for all; it should be revised after one year of operation based on actual consumption records. This is more cost-effective than allocating everything at the beginning. For items whose usage suddenly deviates from historical levels, it is also necessary to check whether the operating conditions have changed or the equipment status is alarming.
How to manage inventory
The three essential elements of the spare parts ledger are: location, quantity, and minimum inventory. Registration of retrieval and replenishment after use, triggering procurement when inventory falls below the minimum level, and marking the supply channel and procurement cycle for each spare part on the ledger. When stocking in, check the model and serial number to avoid the embarrassment of having spare parts but not being able to install them; conduct a half-yearly inventory check to clear out slow-moving and obsolete items. Storage should be moisture-proof and dust-proof: electrical parts and rubber parts should be kept separately, with rubber parts stored in a dark place to prevent aging, and chemicals should pay attention to expiration dates. The ledger can be an electronic spreadsheet or a paper booklet, and the form is not limited, the key is that the account, the item, and the card should match.
Key points for spare parts management reference
| Spare parts category | Reserve strategy | Management points |
|---|---|---|
| gasket | Prepare for the consumption in the first quarter | Keep away from light and store flat to prevent aging |
| filter element | Prepare one or two quantities | Replace due to insufficient pressure or time limit |
| Belt bearing | Each prepare one or two pieces | Regular rotation of wear parts |
| Electrical consumable parts | Each prepare one or two pieces | Store damp-proof, first-in first-out |
| Large-scale unit | No inventory backlog | The contract stipulates the time limit for supply |
| special tool | Check and record | Manage together with spare parts in the same warehouse |
Steps for establishing spare parts management
- Filter out the list of standard spare parts based on failure rate and downtime impact;
- Determine the reserve quantity based on the consumption rate and replenishment cycle;
- Establish a ledger: ensure the completeness of three essential elements: location, quantity, and minimum inventory;
- Take-out registration, replenishment after use, and triggering procurement when below the lower limit;
- The random accessories and special tools are inventoried and managed in the same warehouse;
- Conduct a semi-annual inventory to clear out dead stock, and revise the inventory list based on consumption records annually.
Frequently Asked Questions
Should spare parts be purchased from the manufacturer or from the market?
Common parts such as seals and filter elements can be purchased from the market, but attention should be paid to checking the specifications. Special parts related to the overall performance should be sourced from the original manufacturer, with clear model matching and quality responsibility. Each spare part should be marked with the supply channel in the ledger, so that procurement is not done haphazardly.
What's the reason that the spare parts break down just by being left unused?
Natural aging of rubber parts, moisture damage to electrical components, and expired chemicals can all cause spare parts to "fail while sitting idle". When registering spare parts in storage, note the production date, and follow the first-in, first-out (FIFO) principle. Rotate rubber parts based on their storage duration, and conveniently check their status during inventory checks.
How to start with spare parts when taking over a new station?
Starting with reference to the manufacturer's random inventory and fault records from similar sites, we will first prepare consumable parts and electrical wear parts. After operating for half a year, we will revise the inventory based on the actual fault records of this site. This approach is more practical than preparing everything at once.
This article is compiled by Luoyang Wohong Petrochemical Equipment Co., Ltd. The company provides design and manufacturing, skid-mounted customization, installation and commissioning, as well as after-sales operation and maintenance services for three-time oil and gas recovery equipment to gas stations and oil depots. If you need on-site inspection or scheme configuration, please feel free to contact us for discussion.