control valve actuator sizing and valve action selection

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Control Valve Actuator Sizing and Valve Action Selection The materials included in this compilation are for the use of Dwyer Instruments, Inc. potential customers and current employees as a resource only. They may not be reproduced, published, or transmitted electronically for commercial purposes. Furthermore, the Company’s name, likeness, product names, and logos, included within these compilations may not be used without specific, written prior permission from Dwyer Instruments, Inc. ©Copyright 2015 Dwyer Instruments, Inc.

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Page 1: Control Valve Actuator Sizing and Valve Action Selection

Control Valve Actuator Sizing and Valve Action Selection

T h e m a t e r i a l s i n c l u d e d i n t h i s c o m p i l a t i o n a r e f o r t h e u s e o f D w y e r I n s t r u m e n t s , I n c . p o t e n t i a l c u s t o m e r s a n d c u r r e n t e m p l o y e e s a s a r e s o u r c e o n l y . T h e y m a y n o t b e r e p r o d u c e d , p u b l i s h e d , o r t r a n s m i t t e d e l e c t r o n i c a l l y f o r c o m m e r c i a l p u r p o s e s . F u r t h e r m o r e , t h e C o m p a n y ’ s n a m e , l i k e n e s s ,

p r o d u c t n a m e s , a n d l o g o s , i n c l u d e d w i t h i n t h e s e c o m p i l a t i o n s m a y n o t b e u s e d w i t h o u t s p e c i fi c , w r i t t e n p r i o r p e r m i s s i o n f r o m D w y e r I n s t r u m e n t s , I n c .

© C o p y r i g h t 2 0 1 5 D w y e r I n s t r u m e n t s , I n c .

Page 2: Control Valve Actuator Sizing and Valve Action Selection

Control Valve ActuatorO v e r v i e w

D w y e r ’ s H I - F l o w S e r i e s c o n t r o l v a l v e s h a v e p n e u m a t i c a c t u a t o r s t h a t m o d u l a t e t h e v a l v e f o r fl o w c o n t r o l

T h e o p e n i n g , c l o s i n g a n d t h r o t t l i n g o f t h e v a l v e p l u g i s a c c o m p l i s h e d b y v a r y i n g t h e a i r p r e s s u r e t o t h e d i a p h r a g m i n t h e a c t u a t o r

Ty p i c a l l y t h e c o n t r o l p r e s s u r e s i g n a l i s 3 t o 1 5 p s i g

T h e r e a r e t w o t y p e s o f a c t u a t o r s A i r - To - L o w e r A i r - To - R a i s e

Page 3: Control Valve Actuator Sizing and Valve Action Selection

Control Valve ActuatorO v e r v i e w

I n A i r -To - L o w e r a c t u a t o r s , a s t h e p r e s s u r e s i g n a l i s i n c r e a s e d , t h e d i a p h r a g m p u s h e s d o w n , m o v i n g t h e s t e m a n d p l u g d o w n , a n d c o m p r e s s i n g t h e r a n g e s p r i n g

A s t h e p r e s s u r e s i g n a l i s d e c r e a s e d , t h e r a n g e s p r i n g p u s h e s t h e d i a p h r a g m u p , m o v i n g t h e v a l v e s t e m a n d p l u g u p

Page 4: Control Valve Actuator Sizing and Valve Action Selection

Control Valve ActuatorO v e r v i e w

I n A i r -To - R a i s e a c t u a t o r s , a s t h e p r e s s u r e s i g n a l i s i n c r e a s e d , t h e d i a p h r a g m p u s h e s u p , m o v i n g t h e s t e m a n d p l u g u p , a n d c o m p r e s s i n g t h e r a n g e s p r i n g

A s t h e p r e s s u r e s i g n a l i s d e c r e a s e d , t h e r a n g e s p r i n g p u s h e s t h e d i a p h r a g m d o w n , m o v i n g t h e v a l v e s t e m a n d p l u g d o w n a s w e l l

Page 5: Control Valve Actuator Sizing and Valve Action Selection

Control Valve BodyO v e r v i e w

T h e H i - F l o w c o n t r o l v a l v e s e r i e s o ff e r s t w o t y p e s o f v a l v e b o d i e s , P u s h -To - C l o s e , a n d P u s h -To - O p e n

I n P u s h -To - C l o s e , t h e v a l v e s t e m m o v e s d o w n w a r d , p u s h i n g t h e v a l v e p l u g c l o s e r t o t h e s e a t i n t h e v a l v e b o d y

T h i s m o v e m e n t d e c r e a s e s t h e fl o w t h r o u g h t h e v a l v e

Page 6: Control Valve Actuator Sizing and Valve Action Selection

Control Valve BodyO v e r v i e w

I n P u s h -To - O p e n , t h e v a l v e s t e m m o v e s d o w n w a r d , p u s h i n g t h e v a l v e p l u g a w a y f r o m t h e s e a t i n t h e v a l v e b o d y

T h i s m o v e m e n t i n c r e a s e s t h e fl o w t h r o u g h t h e v a l v e

Page 7: Control Valve Actuator Sizing and Valve Action Selection

Control Valve ActionO v e r v i e w

W i t h t h e c h o i c e o f a c t u a t o r s , A i r -To - R a i s e o r A i r -To - L o w e r ; a n d v a l v e b o d i e s , P u s h -To - C l o s e o r P u s h -To - O p e n ; t h e p r o p e r a c t i o n o f t h e v a l v e c a n b e s e l e c t e d f o r t h e a p p l i c a t i o n , d i r e c t a c t i n g o r r e v e r s e a c t i n g

C o n s i d e r a t i o n s h o u l d a l s o b e t a k e n f o r t h e f a i l p o s i t i o n o f t h e v a l v e , w h i c h i s w h a t t h e v a l v e w i l l d o o n l o s s o f t h e c o n t r o l s i g n a l a i r

Page 8: Control Valve Actuator Sizing and Valve Action Selection

Control ValveO v e r v i e w

A P u s h -To - C l o s e v a l v e b o d y w i t h a n a i r - t o - r a i s e a c t u a t o r w i l l h a v e a v a l v e a c t i o n o f a i r - t o - o p e n a n d s p r i n g c l o s e d

T h i s i s a n o r m a l l y c l o s e d v a l v e a n d i s r e v e r s e a c t i n g

Page 9: Control Valve Actuator Sizing and Valve Action Selection

Control ValveO v e r v i e w

A P u s h -To - O p e n v a l v e b o d y w i t h a n a i r - t o - l o w e r a c t u a t o r w i l l h a v e a v a l v e a c t i o n o f a i r - t o - o p e n a n d s p r i n g c l o s e d

T h i s i s a n o r m a l l y c l o s e d v a l v e a n d i s r e v e r s e a c t i n g

I t h a s t h e a d d e d s a f e t y f a c t o r t h a t t h e u p s t r e a m p r e s s u r e w i l l c l o s e t h e v a l v e o n c o n t r o l s i g n a l a i r l o s s

Page 10: Control Valve Actuator Sizing and Valve Action Selection

Control ValveO v e r v i e w

A P u s h -To - o p e n v a l v e b o d y w i t h a n a i r - t o - r a i s e a c t u a t o r w i l l h a v e a v a l v e a c t i o n o f a i r - t o - c l o s e , s p r i n g o p e n

T h i s i s a n o r m a l l y o p e n v a l v e a n d i s d i r e c t a c t i n g

Page 11: Control Valve Actuator Sizing and Valve Action Selection

Control ValveO v e r v i e w

A P u s h -To - c l o s e v a l v e b o d y w i t h a n a i r - t o - l o w e r a c t u a t o r w i l l h a v e a v a l v e a c t i o n o f a i r - t o - c l o s e , s p r i n g o p e n

T h i s i s a n o r m a l l y o p e n v a l v e a n d i s d i r e c t a c t i n g

I t h a s t h e a d d e d s a f e t y f a c t o r t h a t t h e u p s t r e a m p r e s s u r e w i l l o p e n t h e v a l v e o n c o n t r o l s i g n a l a i r l o s s

Page 12: Control Valve Actuator Sizing and Valve Action Selection

Actuator SizingO v e r v i e w

T h e a c t u a t o r m u s t b e s i z e d t o b e l a r g e e n o u g h t o s h u t - o ff t h e v a l v e a g a i n s t s y s t e m p r e s s u r e o n t h e v a l v e p l u g

T h e H i - F l o w l i n e c o m e s i n t h r e e a c t u a t o r s i z e s w i t h a v a r i e t y o f r a n g e s p r i n g s i z e s a c c o r d i n g t o t h e s h u t - o ff p r e s s u r e n e e d e d

Va l v e s i z i n g c h a r t s o n t h e D w y e r w e b s i t e a n d i n t h e D w y e r c a t a l o g s h o w t h e m a x i m u m s h u t - o ff p r e s s u r e f o r e a c h s i z e v a l v e w i t h e a c h s i z e a c t u a t o r

Page 13: Control Valve Actuator Sizing and Valve Action Selection

Actuator SizingO v e r v i e w

W h e n o r d e r i n g a v a l v e , t h e m a x i m u m u p s t r e a m p r e s s u r e w i l l n e e d t o b e s p e c i fi e d a n d t h e s p r i n g s i z e i s a u t o m a t i c a l l y c h o s e n a c c o r d i n g l y

T h e r a n g e s p r i n g h a s a n o p e r a t i n g r a n g e o f s h u t - o ff p r e s s u r e s t h a t i t w i l l o p e r a t e w i t h , a n d t h e a c t u a t o r h a s a n a d j u s t m e n t f o r fi e l d c a l i b r a t i o n f o r s h u t - o ff p r e s s u r e w i t h i n t h a t s p r i n g r a n g e

I t i s b e s t t o a d j u s t t h e v a l v e i n t h e a p p l i c a t i o n s o t h a t i t o p e r a t e s a t t h e p a r t i c u l a r s h u t - o ff p r e s s u r e i n t h e a p p l i c a t i o n l i n e