Hey there, if you’ve ever spent time hunting for O-rings for anything from a backyard pool pump to a scuba regulator, you’ve probably run into “water resistance” as a top priority— and if you’re here asking about More O Rings specifically, you’re not alone. I’ve been supplying these little workhorses for over 8 years, and I can’t tell you how many customers reach out panicking, “Will these actually hold up underwater?” Let me cut through the noise and give you the real, science-backed tea on what our O-rings can (and can’t) do. More O Ring
First off, let’s get one thing straight: not all O-rings are built the same, and that goes double for water. A lot of people think “water resistance” is a one-size-fits-all label, but it’s actually a spectrum— and More O Rings sit in a really useful sweet spot for most everyday and semi-demanding water applications. Let’s start with the basics of why an O-ring even works for sealing water: they need to be flexible enough to stretch and conform to surfaces, strong enough to hold that shape under pressure, and resistant to breaking down when exposed to H2O over time. The rubber compound we use for our standard More O Rings is nitrile butadiene rubber (NBR), if you want the technical term, but I’ll keep it simple: it’s a synthetic rubber that’s way better with water than, say, natural rubber (which rots fast) or silicone (which is too squishy for high-pressure jobs). That’s not to say NBR is perfect, but it’s the gold standard for most water-focused sealing tasks, and our specific blend? We tweak the NBR mix with extra binders and anti-oxidants because we tested early on that generic O-rings start to crack after 2–3 years submerged, and our customers were tired of replacing them that often.
Now, let’s talk about pressure, because that’s a big one most people overlook. If you’re using an O-ring on a garden hose bib, that’s 40–60 PSI max— no big deal. Submerge that same O-ring in a swimming pool 10 feet deep? That’s another 4.3 PSI per 10 feet, so 44–63 PSI total, still fine. Take that same O-ring and put it in a well pump at 100 PSI? Maybe, but it might not hold as long. Our More O Rings are rated for continuous water pressure up to 150 PSI, and intermittent pressure spikes (like when a faucet slams shut) up to 200 PSI. I’ve had a customer use them for his boat’s below-deck bilge pump for 5 years straight, no leaks, and he tells me that’s way better than the cheaper O-rings he was buying from the hardware store that would blow out every season. That said, if you need something for deep-sea diving (100+ feet, thousands of PSI), our standard NBR O-rings aren’t it— we have a line of fluorocarbon (FKM) O-rings for that, but those are More O Rings too, just for heavier duty.
Next up, chemical exposure, because water isn’t just H2O. A lot of times when people ask about water resistance, they’re actually dealing with chlorinated pool water, saltwater, or even water with a little bit of detergent (for washing machine hoses, say). Our standard NBR O-rings handle fresh water and chlorinated tap/pool water super well— we ran a test batch submerged in 2 ppm chlorine water for 12 months, and they lost less than 5% of their tensile strength, which is nothing compared to generic O-rings which lost 15–20% in the same time. Saltwater is a tiny trickier: salt is mildly corrosive, and over long-term submersion (like 6+ months), it can start to break down rubber a little faster. That’s why I always tell customers if they’re using our O-rings in saltwater (like for a dock lift or a jet ski’s seal), to rinse them with fresh water every month to keep the salt from sitting on them 24/7. We do have a saltwater-resistant blend of NBR, though— we call it our Marine Grade More O Rings— and those can handle full saltwater submersion for up to 18 months straight with minimal degradation, no rinsing required.
Wait, let’s clear up a common myth: “waterproof vs. water-resistant”. A lot of people use these words interchangeably, but they’re not. Waterproof means something can hold back water indefinitely under any pressure— that’s things like a watch’s screw-down crown, or a submarine’s hatch seal. Water-resistant means it’s designed to resist water intrusion for a set period, under specific conditions. Our More O Rings are water-resistant, not fully waterproof— that’s a key distinction. For example, if you use a More O Ring to seal a garden hose connection, it’s going to keep water from leaking out as long as the connection is tight and the pressure is under 150 PSI. But if you submerge that entire hose in a bucket of water and crimp the end tight? Wait, no— actually, the hose is full of air, so it would just hold, but if you had a small gap, it might seep in over time. Our O-rings aren’t for sealing against full hydrostatic pressure over years (that’s what heavy-duty industrial FKM O-rings are for), but for 99% of the people reading this— homeowners, small business owners, even hobbyists— that’s more than enough.
Let’s throw in some real customer examples to make this concrete, because numbers don’t mean as much as actual use cases. Last year, I got an email from a guy named Mike who fixes vintage tractors. He needed O-rings for the hydraulic lines on his 1952 John Deere, which he uses to mow his 5-acre pasture. He said the old O-rings he was using would leak hydraulic fluid when they got wet (hydraulic fluid is basically oil, so that’s a whole other thing, but he mentioned they’d also start crumbling after a few months in the damp grass). He ordered 20 of our standard More O Rings, and 6 months later he sent me a photo of his tractor’s hydraulic connection, no leak, and texted, “These are the first O-rings I’ve used that didn’t turn to goop after the first rain.” Another one: a local coffee shop owner who used our O-rings for their under-sink water filtration system. They were going through O-rings every 2 months because the chlorinated tap water and occasional vinegar descaling agent ate through them. He switched to our Chlorine-Resistant More O Rings, and they’re still going strong 10 months later. That’s exactly the kind of feedback that makes me proud of what we do— we’re not selling a fancy “waterproof” lie, we’re selling something that works for real, everyday water jobs.
Now, what are the limits? No product is perfect, so I don’t want to oversell this. Our More O Rings shouldn’t be used for long-term submersion in hot water over 212°F (obviously, that’s boiling) or even sustained hot water over 180°F— NBR starts to degrade when it’s that hot, so for hot tubs or water heaters, we recommend our high-temperature NBR blend rated up to 250°F. Also, if you’re dealing with water that has strong chemicals, like bleach or acids, our standard NBR will break down pretty fast— for those, you’d want FKM O-rings, which we also carry under the More O Rings brand, though they’re a little pricier. And like I said earlier, if you’re going deep underwater (scuba diving, underwater construction), stick to FKM or even silicone for extreme depths. Most people don’t need that, but it’s good to know the line.
Wait, one more thing that a lot of people don’t think about: installation. An O-ring is only as good as how you put it on. If you stretch it too tight, or scrape it with a sharp edge when you’re installing it, even the best water-resistant O-ring will leak. I always tell customers to lubricate O-rings with a silicone-based lubricant (not petroleum jelly, that eats rubber!) before installing, make sure the groove it’s sitting in is smooth and free of debris, and don’t twist it when you’re sliding it into place. That’s a quick step that makes a huge difference in how long the O-ring holds up in water, no matter the brand.
At the end of the day, when a customer asks, “What’s the water resistance of More O Rings?” my answer is this: for 95% of common water applications (garden hoses, pool filters, washing machines, boat seals, hydraulic lines, faucet connections), our O-rings deliver consistent, leak-free performance for 2–5 years, depending on use. We don’t make any wild claims about being “100% waterproof forever” because that’s not realistic for a rubber seal that’s meant to flex and hold pressure. We make O-rings that work for real people, solving real water sealing problems, without overcharging for a label that doesn’t mean anything.
If you’re working on a project and you’re not sure which More O Ring is right for your water-related job— whether it’s a small replacement for a leaky faucet, a bulk order for a commercial pool, or anything in between— don’t hesitate to reach out. We’re not just a supplier, we’re guys who’ve been in the O-ring game long enough to know what works and what doesn’t, and we’re happy to help you find exactly what you need. Just send over the details of your project, and we can chat through it.
Fluorosilicone O Ring References
- Rubber Manufacturers Association. (2021). NBR O-Ring Performance in Water-Based Environments. RMA Technical Bulletin TB-007.
- Marine Industry Seal Council. (2022). Long-Term Durability of Elastomeric Seals in Saltwater Applications. MISC Report 12-04.
- International Organization for Standardization. (2019). ISO 3601-1: Elastomeric O-Rings for Fluid Power— Part 1: Dimensions, tolerances and identification.
Zhejiang Jiacheng New Material Co., Ltd.
Zhejiang Jiacheng New Material Co., Ltd. is one of the most professional more o ring manufacturers and suppliers in China, specialized in providing high quality customized products. We warmly welcome you to buy or wholesale more o ring in stock here from our factory. Contact us for quotation and free sample.
Address: #64 Anjiang Road, Jianshan New Zone, Huangwan Town, Haining City, Jiaxing City, Zhejiang Province
E-mail: jcseal_zhu@126.com
WebSite: https://www.sjkseal.com/
