Ebay water pump safe for drinking water? - Page 1
Forum section: electronics / general

author: Tuppe
author_rank: Contributor
timestamp: April 08, 2015, 01:38:03 pm
content: Hello, I'd like to ask some peer insight before I poison myself.Is there any reason why these cheap Ebay water pumps would be hazardous to pump drinking water?I'm actually using this for coffee maker, so it will be (almost) boiled before use.I got one of these:http://www.ebay.com/itm/New-Submersible-Water-Pumps-DC-Motor-Pump-3V-6V-120L-H-Low-Hot-/141518623847?pt=LH_DefaultDomain_15&hash=item20f32ad467I don't see why it would contaminate the water if I have cleaned the pump with hot water & dishwasher liquid before the first use, but I might be missing something obvious. Would a plastic pump from China have any sort of hazardous solvent in the material etc.?I couldn't find any alternative 5V pump for small hoses, so I tried that one. Please recommend if you know some good alternatives that WON'T kill the user.Thanks for reading!

author: Zero999
author_rank: Super Contributor
timestamp: April 08, 2015, 02:20:46 pm
content: If you're unsure, ask the seller.The problem is, some materials used in the construction may be harmful or just taste bad. For example phthalates and lead are often added to PVC which may leach out into the water.http://en.wikipedia.org/wiki/Polyvinyl_chloride#Plasticizers

author: KJDS
author_rank: Super Contributor
timestamp: April 08, 2015, 02:24:20 pm
content: I know a reasonable amount about large submersible pumps but little experience with these little ones.Submersible pumps come in a variety of forms. Some have no bearings, and I suspect that one with a life of 500 hours is like that. Some have grease filled metal bearings and the grease slowly seeps out contaminating the water. Whilst I doubt diluted grease will kill you, it won't do much for your coffee flavour.Expensive submersible pumps have ceramic bearings that rely on water as lubrication and for something intended to last then I'd find one of these.It may be worthwhile visiting somewhere local that sells fish tanks, fish being more sensitive to polluted water than the average human.

author: Ian.M
author_rank: Super Contributor
timestamp: April 08, 2015, 02:28:11 pm
content: It isn't at all likely to kill you but as the others have said, may make the coffee taste bad, especially if the shaft seal is something cheap and nasty or the shaft is a low grade of stainless steel.If you want safety, get a pump sold for potable water use, e.g. as a spare part for a beverage maker, or for RV (caravan) or boat potable water systems.If you want to live slightly more dangerously, use an aquarium pump. If its designed and constructed not to taint the water and kill the fish, it wont be harmful to you.OTOH if you've run it for 24H recycling the same cup of water and it hasn't tainted it, its unlikely to do you any significant harm.

author: Tuppe
author_rank: Contributor
timestamp: April 08, 2015, 03:17:48 pm
content: Thanks for the fast information everyone! I might take a one test, but probably subside from continuous use just in case of phthalates etc. that Hero999 pointed out."If you're unsure, ask the seller."For these chinese no-brand products, I'd assume that not even the manufacturer knows thatNevertheless, I just found a trustworthy option from US manufacturer "lightobject":http://www.ebay.com/itm/Mini-6V-Food-Grade-High-temperature-water-pump-for-coffee-pot-/161123088132?pt=LH_DefaultDomain_0&hash=item2583af3704#shpCntIdhttp://www.lightobject.com/High-temperature100C-DC-6V-1LMin-15GPH-mini-Water-Pump-Food-grade-P510.aspxToo bad that the postage for me will double the price. But I think that this pump would even suit for a legitimate product.Chinese have copied the same exact pump, I wonder if this knockoff is totally safe:http://www.ebay.com/itm/250722722777Atleast that's not dirt cheap...

author: sleemanj
author_rank: Super Contributor
timestamp: April 08, 2015, 10:37:38 pm
content: Caution should be exercised with those style of small submersible style pumps, there is quite an abundance of salvaged ones of these in China (I don't know why, but there is from multiple vendors and seems to be a near inexhaustible supply) accordingly they vary in terms of cleanliness, noise and function, and you won't know what it was used for in it's past life (I think small water fountains, I think).If you trust the seller is truthful when they say it's new and unused, maybe, but personally I never take the seller's word for anything.Here is a similar one I disassembled...The motor is a close (not tight) fit into the housing, it has a small O ring on the shaft, the shaft protrudes through the plastic and the impeller fits directly onto it. The entry of the wires into the top cap is epoxied to provide waterproofing.

author: dannyf
author_rank: Super Contributor
timestamp: April 09, 2015, 12:26:38 pm
content: QuoteYou probably want to ask the opposite question: is there any reason that you think they are safe?When it comes to things you put in your body, it pays to be careful.

author: Tuppe
author_rank: Contributor
timestamp: April 09, 2015, 01:25:50 pm
content: Quote from: dannyf on April 09, 2015, 12:26:38 pmWell, I thought that if there's no reason that the materials would contaminate the water, I wouldn't think manufacturers would go out of their way to make it so. I'd assume they try to have the target range as wide as possible, without spending a dime more for the materials.But sleemanj brought good points too, I don't know if these parts are reused. The motor is so cheap that I think it will die way before reuse, but casing materials could be reused.Due the good reasons brought up, I will refrain from the consuming part of my test. I might go for gravity fed system, or proper pumps that atleast state they're safe to drink.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: April 10, 2015, 01:47:53 am
content: submersible pump is the wrong tool for the job anyway. For food grade and medical application peristaltic pumps are used with food grade silicone tubing.

author: LabSpokane
author_rank: Super Contributor
timestamp: April 10, 2015, 05:24:51 am
content: Quote from: chickenHeadKnob on April 10, 2015, 01:47:53 amThere's several options for budget peristaltic pumps on ebay for $8-40 depending on the volume. They actually work well. I've bought a bunch and they've all been good. Just dump the supplied tubing for known silicone tubing of the correct size and durometer.Whatever you do, don't trust plastic of unknown origin for a food application. You have no idea what could have been salvaged and mixed in as scrap material. It is standard practice in the plastic industry to regrind scrap material and mix it back in. It is not allowed in the US for food applications, but in China, who knows. I wouldn't take the chance.

author: Tuppe
author_rank: Contributor
timestamp: April 10, 2015, 04:23:46 pm
content: Quote from: chickenHeadKnob on April 10, 2015, 01:47:53 amI strongly disagree, I chose submersible pump for 3 reasons; It's quieter(pump inside water), more compact(no external motors cabinet) and faster.Basic peristaltic pumps are awfully slow(100mL/min! it takes 2 minutes to get one cup!) and need specially durable tubing, or else it will fail due to the rubbing. I don't think coffee water is so vital that it would actuallyrequirea peristaltic pump. It's more for medical applications.I just don't see why there would be a serious problem using one like this:http://www.lightobject.com/High-temperature100C-DC-6V-1LMin-15GPH-mini-Water-Pump-Food-grade-P510.aspxIf there was, I don't think these pumps would even exist.

author: Zero999
author_rank: Super Contributor
timestamp: April 10, 2015, 07:55:46 pm
content: Quote from: Tuppe on April 10, 2015, 04:23:46 pmThe main advantage of peristaltic pumps is the volume can be very accurately controlled.If it's not that critical then that pump appears to be great value: you're better of spending slightly more to get a reliable and safe product. I wouldn't use any of those other cheap pumps off ebay for anything more than fountains and toys.

author: SeanB
author_rank: Super Contributor
timestamp: April 10, 2015, 08:12:39 pm
content: For peristaltic pumps you look at Watson Marlow, and for the tubing Marprene. Then you look at the price, and use the tubing very sparingly. I still have a half meter of the tubing around, in the box it came in, though originally it was a 5m roll.

author: LabSpokane
author_rank: Super Contributor
timestamp: April 10, 2015, 09:43:17 pm
content: Quote from: Hero999 on April 10, 2015, 07:55:46 pm

author: Tuppe
author_rank: Contributor
timestamp: April 11, 2015, 08:09:58 am
content: Quote from: Hero999 on April 10, 2015, 07:55:46 pmI use 5$ flow meter("coffee maker" use claimed, dont see much reason to doubt it) to control the volume, which works fine. In this case, slightly more means up to 20€. Yes, I would never use unspecified eBay items for commercial product. And as said in this topic, I wouldn't use them for consumption use either.But the Lightobject I linked wasnot ebay, it's a US manufacturer. I don't see any doubts with it.Quote from: SeanB on April 10, 2015, 08:12:39 pmWhen I looked at the prices, even the pump head was over my yearly budget. Total overkill. No reason to use biomedical grade equipment for this use, even if it was commercial. According to what I've searched, not even real water machines use peristaltic pumps.Quote from: LabSpokane on April 10, 2015, 09:43:17 pmYou are right, when we're talking about cheap Ebay pumps that don't even try to claim drinking water use, but I don't see any reason, why specifically designed food grade pump ordered directly from reliable US manufacturer(Lightobject) would be a hygiene/contamination risk in any wayPeristaltic pump 100ml/min speed is also a total deal breaker.I need to keep my costs in sensible values. I don't see any reason to spend more than 20€ for this project. Even professional water systems don't do overboard with the pumpsI'm not planning to do a product of this, but I'm a studying to be a product designer so I want to train as if I was designing a product every time. I just cannot use 100$ peristaltic medical grade pumps when there's 15$ option available. I might make another copy of this kit for my brother or friends at best, but I try to design it as if it was going on store shelve. That means not only safety, but also price considerationI usually use chinese knockoff components for prototypes if there's reliable manufacturer option available that's plug&play compatible in case of commercial application.