Imported brand valves are indeed good, but replacing parts with them is a hassle – the lack of versatility is really problematic

Thread Content

Those who have used imported valves in factories know that the quality of these valves is excellent; they can be used for years without any problems. But once a problem arises and spare parts are needed, it becomes a real headache – either they’re unavailable, extremely expensive, or the specifications don’t match. Why are spare parts for imported valves so hard to find? The root of this problem is that many imported valves have their own \"traditional designs.\" For flanged ball valves with a DN50 size, those made in China generally have similar valve stem lengths, packing dimensions, and seat specifications; they can be installed using different brands as well. But the imported ones are different: the valve stem of brand A is 2 millimeters longer than that of brand B, and the outer diameter of the valve seat of brand C is 1 millimeter larger than that of brand D. If the size is off by a little, it won’t fit. Some factories have encountered this situation: the diaphragm of an imported control valve broke, and the distributor charged 3,000 yuan for a replacement diaphragm, with a delivery time of 6 weeks. The factory couldn’t wait that long, so I measured the dimensions myself and found a domestic manufacturer of diaphragms to produce one; it cost 300 yuan to make one, and its performance is just as good. But not all spare parts can be handled in this way – for high-precision components such as valve seats and valve cores, the precision achieved through self-manufacturing is not sufficient, so they must be purchased from the original manufacturer. What is the fundamental reason for the poor versatility of spare parts? Reason 1: The need for technical confidentiality. When designing and manufacturing valves, valve manufacturers incorporate unique designs in key fitting dimensions and details to prevent their technology from being easily replicated, which results in spare parts that are not interchangeable. Reason two: Considerations of commercial interests. The sale of spare parts is an important source of profit for valve manufacturers. Statistics show that the profit margin from spare parts sales can reach 30%–40% of the overall sales profit margin; therefore, manufacturers are reluctant to give up this lucrative segment. Special design for specific operating conditions: There is also a situation where some designs of inlet valves are intended to suit particular operating conditions, not deliberately to prevent their use in other contexts. For example, the stem of valves from a certain brand may have undergone a special nitriding treatment, or the seat material might be a special alloy; domestic standard components simply cannot achieve such performance levels. In this case, although buying original spare parts is expensive, it’s worth it. The necessity of replacing imports with self-sufficient solutions actually reflects a broader trend: the replacement of imports with self-developed alternatives for critical valves. In recent years, the pace of domestic substitution in high-end valve sectors such as nuclear power, LNG, and ultra-supercritical thermal power has accelerated significantly. Especially when it comes to maintenance spare parts, one should not always be held back by others. Here are a few suggestions for users: If your factory imports a large number of valves, you might consider the following points: First, purchase essential valve spare parts simultaneously when acquiring equipment, or enter into long-term supply agreements with suppliers to lock in prices and delivery times. Second, for some widely used spare parts (such as gaskets and seals), domestic manufacturers are commissioned to replicate them or develop localized versions, in order to establish one’s own spare parts inventory. Third, when selecting new projects, it is advisable to choose international brands that have manufacturing facilities in China and ensure a reliable supply of spare parts, or to opt for mainstream domestic brands. Fourth, establish a ledger for the full life-cycle management of valves, recording the spare parts models and interchangeability information for each valve. The quality of imported valves is indeed good, but the issues related to the versatility of spare parts are real and significant. When selecting and purchasing equipment, factories should not consider only the price of the equipment itself, but also take into account the maintenance costs over its entire lifetime.