Ua hoʻolālā ʻia ka valve check swing, non-return valve, i mea e pale ai i ka hoʻohuli ʻana o ke kahe i loko o kahi ʻōnaehana paipu.Hoʻohana ʻia kēia mau kiwi e ka mea kahe i loko o ka pipeline.ʻO ke kaomi o ka wai e hele ana i loko o ka ʻōnaehana e wehe i ka valve, ʻoiai ʻo ka hoʻohuli ʻana o ke kahe e pani i ka valve.Hoʻopau ʻia ka pani ʻana e ke kaumaha o ka mīkini loiloi, ma ke kaomi hope, ma kahi pūnāwai, a i ʻole ma ka hui pū ʻana o kēia mau ala.

ʻO ka pahu hoʻopaʻapaʻa swing 800lbs  no ka liʻiliʻi liʻiliʻi kiʻekiʻe kiʻekiʻe kiwi loiloi, i hana ʻia e ke kila forged.we hana maʻamau iā lākou i loko o ka swing check valve, piston check valve (lift check valve).Loaʻa i ʻekolu mau hoʻolālā pāpale.ʻO ka hoʻolālā mua ʻo ia ka Bolted Bonnet, me ka hui kāne a me ka wahine, ka pahu ʻeha spiral, i hana ʻia ma F316L/graphite.Loaʻa nō hoʻi ke apo hoʻopaʻa ʻana ma ke noi.ʻO ka lua o ka hoʻolālā ʻana, ʻo ia ka pāpale welded, me kahi hui wili ʻia a hoʻopaʻa ʻia.Ma ke noi e loaʻa kahi hui welded ikaika komo piha, ʻo ka hoʻolālā hope loa ka bonnet seal pressure, ʻo ia ka mea i hoʻolālā ʻia no nā kiʻekiʻe kiʻekiʻe.