? Product Description ? 1.Application?and?characteristic Position?device?(stop?ring),?called?position?ring,?stop?circular,?brake?ring,?etc.?It?is?used?to?limit?the?centralizer?or ?cement?basket?slip?on?casing.?It?is?devided?into?mobile?screw?type,?fixed?screw?type?and?buckle?type. ? ? 2.?Install?and?use?method a.?When?use?mobile?screw?type?stop?collar,?slip?over?the?casing,?tighten?the?screws?using?wrench. b.?When?use?fixed?screw?stop?collar,?put?the?collar?around?the?casing,?insert?the?screw,?and?knock?into?screws?by?hammer. c.?when?install?buckle?type?stop?collar,?buckle?the?stop?collar?onto?the?casing,?lock?with?pin,?knock?into?the?screws. ? Specification ?

Specification(inch)	I.D.(mm)	O.D.(mm)	Holding Force (KN)
13-3/8	338	350	40
10-3/4	272	284	40
9-5/8	245	257	40
8-1/8	206	218	30
7-5/8	193	285	30
7	177	189	30
5-1/2	139	151	30
5	126	138	24
4-1/2	114	126	24

? Packaging & Shipping ? Our Services ? All products purchased in our company are guaranteed to keep in good repair for one year. If quality problems happen in guarantee period, our company will maintain for free. Additionally, our company provides technical support and fittings for life. After-sales service isn't restricted by time and we will assign technical personnel to solve your problems immediately after receiving telephone and hear feedback idea of users and deal with them in time. If you are caught in some problems when using our products, welcome to contact us at any time. ? ? FAQ ? 1.?Why?do?you?choose?our?company? We?have?a?long?development?history?in?the?industry?in?China;?the?products?and?technology?have?been?improved?to?a?higher?level.Our?strong?technical?team?can?ensure?high?quality?products?. ? 2.How?can?we?guarantee?our?quality? Every?time?we?will?inspect?our?factories?first.?This?inspect?will?include?the?persons,?the?present?products,?their ?scale?etc.?If?everything?is?OK,?we?will?start?to?cooperate.?During?production?,?we?will?go?to?the?factories?to?test?the?products?to?guarantee?the?products?has?good?quality.?If?it?doesn't?meet?our?requirement,?the?goods?will?be ?refused.? ? 3.?Do?we?have?price?advantage? We?have?our?own?factories?and?outstanding?working?team?.And?also?establish?long?term?business?relationship?with?many?manufactories?in?China?market.?So?we?can?get?more?competitive?price?from?them.?? ? ? ? Company Information ??Puyang Zhongshi Group Co., Ltd. was founded in 1996, which is the restructured enterprise of Central Plains oilfield branch company of SINOPEC . The company registered capital is 60.83 million yuan, with annual output value 200 million yuan, 580 employees, including more than 160 technical and administrative staff . Oil machinery is our main products, the leading products include pumping unit, subsurface sucker rod pump, wellhead (Christmas Tree), pressure vessels, drilling solid control series products and cementing accessories. We had attained ISO 9001 in 1998 and API Certificates in 2002 . ?