A ship valve factory in Jining, Shandong, has long relied on traditional castings during valve manufacturing, but has faced quality issues such as internal pores and sand holes in the valve body, leading to unstable valve sealing, high maintenance frequency, and impacts on ship operation safety and maintenance costs. After multiple process comparisons and on-site inspections, the factory ultimately selected stainless steel forgings supplied by Jianing Forging as an alternative, comprehensively optimizing the performance of core valve components.

Case Summary

This ship valve factory mainly produces medium and high-pressure valves for marine environments, with high requirements for material strength, corrosion resistance, and sealing surface precision. Previously, cast stainless steel parts frequently exhibited defects under complex working conditions, resulting in a high product repair rate. To meet their needs, Jianing Forging customized a batch of 316L stainless steel forgings for valve bodies and key sealing parts. After batch validation, the product pass rate improved.

Customer pain points

The customer faces three prominent issues in the existing process:

• There are defects such as pores and shrinkage looseness inside the casting, and tiny leakage points appear on the sealing surface after processing.
• The material has insufficient density, shortening its service life in corrosive seawater environments, with an average replacement cycle of only 18 months.
• The mechanical properties of each batch of castings fluctuate greatly, and the stability between batches is poor, affecting downstream assembly efficiency.

Product advantages

The stainless steel forging solutions provided by Jianing Forging offer the following values:

• Through multi-directional forging technology, internal pores are eliminated, the material's density is close to theoretical values, and the sealing surface is processed with no microscopic defects.
• Using temperature-controlled forging and solution treatment, grain size reaches above grade 7, and its resistance to chloride stress corrosion is significantly superior to that of castings.
• Each batch of forgings undergoes mechanical and metallographic inspection according to ASTM A182 standards, with traceable data and high batch consistency.

In this case, after the customer switched the valve body, valve cover, and gate plate entirely to Jianing forged stainless steel parts, the valve seal leakage rate dropped to zero, maintenance intervals extended to over five years, and overall manufacturing costs were reduced by about 12%. Currently, Jianing Forging has established a long-term stable supply relationship with the plant, and its products are used in ballast and fire protection systems for various types of ocean-going vessels.