In harsh working conditions such as mining excavation and marine shipping characterized by heavy loads, constant vibration and severe corrosion, the sealing integrity and stability of hydraulic systems directly govern equipment operating efficiency, construction safety and maintenance costs. For a long time, conventional threaded fittings have been widely adopted for all kinds of hydraulic pipeline connections due to their simple structure and low cost. However, complicated working scenarios including mining and marine operations frequently suffer from loose threads, pipeline leakage and pipe bursting failures, which constitute major bottlenecks hindering stable equipment operation. By contrast, SAE hydraulic flanges manufactured in compliance with SAE J518 and ISO 6162 standards feature outstanding vibration resistance, leak-proof performance, high pressure bearing capacity and universal adaptability, gradually replacing traditional threaded fittings as the core connecting components for mining and marine hydraulic machinery.

The most prominent merit of SAE flanges compared with threaded fittings lies in anti-loosening vibration resistance and zero-leak sealing, which perfectly addresses pain points of mining and marine equipment. Mining machinery including roadheaders, tunnel boring machines and mining loaders operates under continuous high-frequency vibration and alternating heavy impact loads. Meanwhile, deck cranes, steering hydraulic systems and hydraulic power units on offshore platforms are subject to constant rocking caused by waves and hull shaking. Conventional threaded fittings rely on thread engagement for locking. Prolonged vibration easily leads to thread loosening and tooth wear, resulting in hydraulic oil leakage and pressure loss. This not only wastes hydraulic fluid and contaminates equipment, but also gives rise to insufficient hydraulic power and sluggish movement. In severe cases, unplanned shutdowns and safety accidents may occur.

SAE flanges adopt a four-bolt symmetrical clamping structure paired with a face O-ring flat sealing design, completely overhauling the sealing mechanism of threaded fittings. The four bolts are tightened evenly in diagonal sequence to deliver uniform stress and superior clamping force, effectively counteracting pipeline displacement induced by equipment vibration and load impact, and fundamentally eliminating connection loosening. In addition, the gap-free flat O-ring sealing is independent of thread precision and far outperforms tapered thread sealing. It maintains zero leakage under high pressure for long-term service, making it ideally suited for mining environments with heavy impact and marine operations with persistent hull shaking.

SAE flanges also outperform threaded fittings drastically in pressure resistance and working condition adaptability. Standard threaded fittings suffer drastically degraded sealing performance and low maximum pressure rating under large-bore high-pressure conditions, failing to meet the operational demands of large mining hydraulic equipment and high-pressure marine hydraulic systems. SAE flanges are divided into Code 61 standard pressure series (maximum 350 bar) and Code 62 high-pressure series (maximum 420 bar), covering all industrial high-pressure hydraulic applications. They deliver stable performance for regular high-pressure oil circuits of mining hydraulic stations and excavation machinery, as well as heavy-duty pipelines of large marine hydraulic power units. For marine environments with heavy salt fog and severe corrosion, SAE flanges made of 304 and 316 stainless steel effectively resist seawater corrosion and oxidation rust, greatly extending service life and remedying the vulnerability of ordinary threaded fittings to rust and damage.

Furthermore, SAE flanges boast practical advantages in installation, maintenance and pipeline layout compatibility. Assembly and disassembly of threaded fittings require rotating pipelines, which easily twists rigid hydraulic tubes and damages flexible hoses. Repeated disassembly and assembly will drastically degrade sealing performance. Split SAE flanges eliminate the need to rotate pipelines, allowing 360-degree free adjustment of pipeline routing to fit compact installation spaces on machinery. They enable quick assembly and disassembly without damaging tubing. For post-operation maintenance, leaking threaded fittings often require full component replacement and pipeline re-routing, incurring high maintenance expenses. In comparison, SAE flanges only need periodic O-ring replacement to restore sealing performance, featuring simple upkeep and low costs that significantly cut downtime for mining and marine equipment maintenance.

At present, with the intelligent upgrading of mining excavation equipment and iteration of high-end marine machinery, hydraulic systems impose increasingly stringent requirements on the reliability and stability of pipeline connections. Traditional threaded fittings can no longer satisfy long-term operation under harsh working conditions. Benefiting from comprehensive strengths including anti-loosening vibration resistance, high-pressure leak tightness, corrosion resistance, easy maintenance and wide compatibility, SAE flanges have become standard connecting hardware for mining construction machinery and marine hydraulic equipment, comprehensively superseding traditional threaded connection solutions. Moving forward, alongside continuous advancement in fluid connection technology, standardized and highly reliable SAE flanges will see broader application in heavy industry and offshore engineering, safeguarding stable operation of premium hydraulic equipment.